Yay, finally a question I can answer, since I'm working for 2 years now on the everyday life of German soldiers in occupied Poland.

A lot has already been said by willOTW, especially about the location. While it is true that Hitler hated Poland, you must see that Hitler wasn't physically in Poland. So, did the soldiers internalize his attitude? First of all, his propaganda didn't have as much impact as you might think in the first few months of the occupation. A lot of soldiers lost contact to propaganda in the first few months. For example, Łódź has been occupied 9th sep. 1939, the first edition of the "Lodzer Zeitung" appeared 12th nov. 1939. This may sound like it wasn't a big thing, but in the time it took the Nazis to establish their cultural politics, the soldiers could actually start to think and question their propaganda image.

"Jedenfalls von der großangelegten Propaganda von der immer in der Heimat gesprochen wurde, spüren wir nichts. Auch zur Aufklärung der Polen hätte sie längst einsetzen müssen. Aber wir kennen ja die Ziele nicht." (GÜNTHER SCHRIEVER-ABELN, to his family, 11.09.1939, Museum für Kommunkation Berlin, 3.2002.7145)

"However, we don't see any of the large scale propaganda, about which the people at home talk about. The intelligence in Poland should have started long ago. But we don't know their goals."

But let's take a look into the actual sources.

How did the soldiers see the Polish people, when they met them the first time?

The soldiers actually believed the German propaganda, and a lot of them wished to be in France instead of Poland. So their first impression was already biased. First of all, the hygiene was described as very bad:

"Abends Quartier in einer engen, stickigen Bauernstube. Sauberkeit und Ordnung kennt man in Polen nicht." (GÜNTHER SCHRIEVER-ABELN, to his family, 10.10.1939, MfK Berlin 3.2002.7145)

"In the evening, accommodation in a narrow, close farmhouse. Cleanliness and order is unknown in Poland."

Plus, the infrastucture was another thing they recognized as very bad:

"Die polnischen Straßen sind unglaublich." (HEINRICH BÖLL, to his family, 19.07.1940, Briefe aus dem Krieg 1939-1945)

The polish streets are unbelievable."

The industry in Poland was seen bad as well, but some writers actually liked the natural atmosphere:

„Ich kann in das Klagelied über die polnische Wirtschaft hier nicht ohne weiteres einstimmen. Aber das liegt wohl daran, daß ich dem „Fortschritt“ zu fremd gegenüber stehe. So erscheinen mir die Holzhäuser mit den Strohdächern als das natürliche Ergebnis der Landschaft." (KONRAD JARAUSCH, to his family, 25.01.1940, "Das stille Sterben...")

"I can't lament about the industry like the others do. Maybe it's because I kind of oppose to the "progress". Thus the wooden houses with stray roofs appear as the natural outcome of the landscape to me."

So to sum this up, the first impression was really akward to the soldiers. HOWEVER, and I was really suprised when this came clear to me, this attitude changed once the soldiers got into touch with the Poland people. I mean, after all, they are still human beings - both the soldiers and the Polish people.

One thing I noticed was, that quite a few soldiers learned polish (with help of polish people, especially priests). Well, this is at first glance a handy thing to do. You would like to want to speak the language so you could buy stuff and tell your polish workers to do the dishes for example. But - thats stuff you can learn in a few days. Nevertheless the soldiers didn't stop learning the language. Why would you learn a language of people, which culture you detest? The answer is simple because you start to learn that the culture is not really worse or better than the German or French, but different. A rather beautiful quote here:

"Es lachte mich an und wollte etwas zu mir sagen, aber ich verstand es nicht. Und auf einmal rollten mir die Tränen aus den Augen. Das sah das Kind und sagte zu seiner Mutter, die auf dem Bündel saß: „Panje puakai" (WILM HOSENFELD, to his family, 08.12.1939)

"It laughed at me and wanted so say something, but I didn't understand it. Suddenly, I started to cry. Then the child said to his mother:"panje puakai".

Hosenfeld probably wanted to say "pan płakał" = the man cried.

So especially to the Polish children, but the other Polish people as well a lot of German soldiers tried to get in touch with:

"Die kleinen Polenkinder hier kennen mich schon und lachen mich an, wenn sie zur Schule gehen." (WILM HOSENFELD, to his family 16.12.1939)

"The little polish children already know me and laugh at me, when they go to school".

German soldiers were not as coldhearted as the steriotype is:

„Der Mann weint. … Meine Kinder sterben vor Hunger. Ich habe nichts mitnehmen können, ich habe kein Geld.“ Er wischt sich mit seinen schwieligen Händen über das Gesicht, hilflos steht er vor mir. Und ich kann ihnen nicht helfen. Das Unglück schneidet mir ins Herz.“ (WILM HOSENFELD, to his family 14.11.1939.)

"The man cried.... my children are starving. I could not take anything with me, I don't have any money. With his brawny hands he wiped over his face, helplessly hes standing in front of me. And I can't help him. The misfortune breaks me my heart."

(Since I notice this will take some time, I will shorten the rest, if any questions are left I can answer them)

The German soliders were also intersted in the Polish girls, and didn't see them as inferior as you might think.

There were even things, that German soldiers valued higher in Poland than in Germany, for example the Heimatliebe (there is no English word for "Heimat"). The soldiers were suprised how much the Polish loved their Heimat and how much they identified with it. Another thing is the Polish hospitality, something that still suprises people when they first come to Poland in our days. Even though the soldiers invaded people, even though they killed polish people, even though they were poor as hell, a lot of families invited soldiers over to their house and offered them a meal (thats the point where a lot of friendships developed, that lasted long after the war was over).

However, one thing didn't change in the course of time: the German felt superior:

"Die Deutschen sind jetzt die Herren. Vor ihnen kriechen nun die Polen." (KURT MARLOW, 07.09.1939, to his friend, MfK 3.2002.0884)

"The Germans are the masters now. The polish creep in front of them".

"Wenn man die Gefangenen sieht traute man ihnen nichts Böses zu, aber wehe wenn ein Deutscher in polnische Gefangenschaft gerät, den martern sie zu Tode. Wir behandeln sie viel zu gut." (JOHANNES HAMM, 17.09.1939, to his family, MfK 3.2002.7184)

"If you see the prisoners, you wouldn't think about any mischief, but once a German get's into polish captivity, they torture him to death. We treat them too well."

However, one last thing I don't want to hide is something I found really interesting, it's when the soldiers speak about a thing they call the "Polish soul".

"Ich beneide diese Menschen! – Mir scheint, sie sind glücklich! – Hier liegt das Geheimnis der polnischen wie auch der russischen Seele: bedingungslose Hinhabe, die bis zur Selbstaufgabe wird. Dieses Polen kann sich niemals ganz verlieren; von hier aus wird es sich wiederfinden. Und dieses neue Polen wird seinen Ausgleich finden, weil wir dieses Polen achten können.“ (WILM HOSENFELD, to his family, Ende September)

"I envy those people! - It appears to me, they are happy! - Here lies the secret of the Polish and Russian soul: absolute devotion, up to self-abandonment. This Poland can never completely lose itself; from here on it will find itself again. And this new Poland will find it's balance, because this Poland we can respect."

I have a lot of quotes like this lying here, so this definately is a thing for the German soldiers.

While this didn't give you an actual answer to your question, I wanted to give some insight into the thing the German saw the Polish people. While it is true that Hitler hated the Polish, it is not true that the soldiers hated them. Sure, they felt superior. But that doesn't necessarily go along with hating them. A lot of soldiers showed quite an interest to the Polish culture (but this was a much bigger thing in France), especially the more educated ones.

I tried to make it as short as possible, so if someone has any questions left, go a long. This comment only covered the first few months of the occupation, but I researched the whole period from 1939-1945.

Some basic works you might want to check out on this aspect:

Jochen Böhler/Stephan Lehnstaedt (Hgg.): Gewalt und Alltag im besetzen Polen 1939-1945, Osnabrück 2012.

Richard C. Lukas: Forgotten Holocaust – The Poles Under German Occupation 1939–1944, New York 1997.

Stephan Lehnstaedt, Okkupation im Osten. Besatzeralltag in Warschau und Minsk 1939-1944, München 2010.

Jacek Andrzej Młynarczyk (Hg): Polen unter deutscher und sowjetischer Besatzung 1939-1945, Osnabrück 2009.

Wlodzimierz Borodziej/Klaus Ziemer (Hg.): Deutsch-polnische Beziehungen 1939-1945-1949. Eine Einführung, Osnabrück 2000.

I hope somebody else can give a more in depth answer, but I will summarize it by saying it mainly comes down to two things: Location and People. These are tied together and impact one another.

Location

The whole German issue with Poland goes back before WWII when Adolf Hitler was advocating for Lebensraum, or living space. Poland being a fairly decent sized country next to Germany was a prime target for German expansion. Also note this is tied up partly with the view of the Aryan race superiority and the view of Slavs and eastern people below "Pure Germans". Poland also provided a direct route into the Soviet Union as well, so it had some strategic value as well. The [siege of Warsaw](http://en.wikipedia.org/wiki/Siege_of_Warsaw_(1939) and bombardment from both sides throughout the war that followed led to widespread destruction of an ancient city. The Germans didn't care much for the poles and waging destructive war through their country, and Stalin didn't mind either. In fact when the Germans invaded they had an agreement with the Soviet Union allowing their own invasion and takeover of the eastern half of the country. Wiki paragraph on Warsaw gives you an idea of how bad it was.

People

Hitler didn't just dislike Slavic people, he hated them. To the west he sometimes talked about a joint Anglo-Saxon domination of Europe with England (though the sincerity of this is doubtful). But the people to the east were Slavs, Jews, and communists that were taking up valuable resources and land for the more pure races. To him they were subhuman and expendable.

The large number of Jews in Poland and particularly Warsaw did not help the situation either. You see many concentration camps set up due to the early invasion allowing for permanent camps being set up as well as large numbers of Jews. In Warsaw they were simply herded together into one large ghetto and cut off, pretty much left for dead. When there smoke of an uprising the Nazis moved in before there could be a fire and absolutely destroyed the place. Wikipedia puts the casualties as high as around 300,000. With the war going poorly at this point and realizing they would loose the city to the Allies soon, the Nazis started to plan to destroy the entire city. As in all of it and come shockingly close to achieving their goal. WWII had an extreme negative impact on Warsaw and Poland as a whole, setting them back. The Soviet Occupation did little to ease the burden either, and there was nothing like Marshal Plan scale rebuilding. Lately there has been an architectural revitalization and slight boom in Warsaw. But many parts were simply never rebuilt or developed.

So in conclusion, take the usual burden of an occupying army. Then add to the fact the occupying army thinks of you as a lesser human. Next have a second invading army that really doesn't think any better of you come in and take over what is left. Also, your country has to experience this for the entire war. Throw in mobile death squads to the mix and you could definitely argue that Poland was one of the countries that had it really really bad.

The history of bad treatment goes back several hundred years (see Partitions of Poland )

Most notable is the period of Third Partition when Poland lost sovereignty for 123 years (from 1795 until just after WWI.

It was a period of forced russification and germanization.

During this time many Germans settled in former polish territories.

After WWI Poland reemerged as and independent country and got some of its former territories back (now with many Germans/Russians living there).

As a result, both Russians and Germans saw Poland as their former territory which is to be reclaimed and unified and Poles living there to be eliminated to stop any future uprisings / claims.

Geopolitically Poland occupies an important area between Germany and Russia. Both Germany and Russia (and earlier the Austro-Hungarians) wished to occupy or control that area as a buffer zone between the two. By controlling that area they could help prevent future invasion and the defense of their country, as well exert influence over their neighbors. This made it a priority to both the national defense of Germany and Russia to have control over that area of land. This is one of the reasons (others have discussed some other reasons) why Poland was important for both Russia and Germany. Add to the fact that Poles tended to be highly nationalistic and became quite the 'problem' for those nations wishing to control them. They would not be subjugated easily, causing hostility with those wishing to do so. In addition having their own ambitions (although rarely being able to pursue them in their history) caused tension.

This led to a worst-case scenario for the Poles during WW2. To be simultaneously invaded from both sides by the Germans and Soviets. The Germans, in addition to trying to eliminate the Jews (of which there were significant numbers in Poland) hoped to quell the Polish to eliminate the Polish resistance in the future. If they could exterminate large numbers of citizens it would severely limit the ability of Poland to resist German occupation. The Soviets intended to do the same themselves (Katyn, Warsaw Uprising) to prevent the Polish intelligentsia from opposing communism and/or Soviet domination. By eliminating significant numbers of military leaders, priests, lawyers, teachers, doctors, and other well off individuals. Basically your influential and intelligent 'leaders' of society, or the ruling class. It was an attempt to neuter the Poles and eliminate potential problems down the road. Racism or bigotry played some role, but was not likely the guiding factor that eliminating the potential Polish threat was. Also do not discount the fact that Stalin was extremely bitter about the defeat/embarassment he faced at the hands of the Poles during the Polish-Soviet War of 1920. I hope this helps out some.

tl;dr - It was an attempt by both the Germans and the Russians to eliminate Polish resistance to their control over the country by devastating Poland and their leadership.

Here's something I've read regarding Polish discrimination stemming from the time when parts of Poland were Galicia.

The Poles are generally regarded as the Irish of the Slav race. And, like the Irish, to quote Gogol, the Slav humorist, they are "laughing a laugh under which are bitter tears." They forget their national humiliation. On their faces is written perpetual agony, and from their conversation, which is, as a rule, superficial when a stranger is present, one gathers the that there is something behind what is said which cannot be spoken, something which, for obvious reasons, it is best ignore or hide.

And here's an entry from a 1913 edition of Old Homes of New Americans describing the lands abandoned by new American immigrants:

For the most part, Galicia is one seemingly interminable prairie; and as one travels across it in winter, it gives him a sense of dreary desolation that few parts of the world suggest.

Subsequently, most of Poland (and the Poles by extension) was regarded only as the farmlands of Eastern Europe nations. Even into the twentieth century, when Poland had a global monopoly on paraffin wax, the region was being exploited:

It had rich petroleum reserves, but the were in they hand of foreign investors, and "only 7 factories emplyed 1,000 workers," which is to say it had virtually no industrial development whatsoever.

Thanks for the comments guys