The main source of distrust came from World War 1. By 1918, Germany just no longer had the resources to keep on fighting. However German military leaders had pretty much spent the whole war telling its home front the war was going well, and now did not want to admit its shortcomings to the public.

So the German military leadership created the myth that "It was not the military, but the German Civilians who had lost their nerve, they claimed. It was the disloyal, revolutionary home front, they accused, that had stabbed the fighting men in the back and betrayed them to their enemies...And the notion of an undefeated military fit with comforting myths about national greatness. In the eyes of many Germans, their new, democratic government symbolized the civilian weaklings who had supposedly betrayed Germany's fighting heroes. This perception in turn undercut the authority of the Weimar Republic".

Sources used: War and Genocide by Doris Bergen

There are some good points here but also some very large glaring issues missing at the moment. I also want to refer back to the question as it is not that Germans were "unsatisfied with democracy." To better understand what I mean you have to understand some key events that took place from 1918-1923 and a bit before the armistice.

The first is that the civilian population of Germany (from rural to urban) and the soldiers were completely fed up with the war by early 1917 and clearly by late 1917. Yes there was the Ludendorff offensive, which raised the troops spirits somewhat, but this was bound the idea that a final push could reign in peace. The lack of food, horrible deaths, disparity, stress on farming, factories, all careers and levels of society was spelled the doom for the Kaiser and also (though less discussed) revitalized distrust of Prussian/Berlin control over the other states. Overall this led to many soldiers and civilians becoming advocates of the MSPD party, the very party which would control the Weimar Republic and announce the "German Republic" on the 9th of November, as it was basically only party pushing consistently for a peace. To summarize, before the war's end distrust throughout all of Germany was at a massive peak at every level of society. Even rural and urban civilians would be caught up in conflict as one controlled the food supply and the other was hungry!

The second point are the, what we call today, conspiracy theories abound at that point. As the war was just devastating to society, civilians and soldiers truly couldn't grasp how it was still going on. The popular belief (basically fact) by 1918 was the rich industrialists and the upper-upper tier of society were benefiting from the war and as such didn't want it over (things ranged from killing off lower classes, annexing more territory, reforming farm plots, just to name a few). I wrote "basically fact" up there because you would be hard pressed to find a soldier who at serving at the Western Front not believing this same with his family back home. Christ, even today it is pretty baffling why it was acceptable to lose millions of men and allow for thousands of civilians to die for literally nothing.

Now all this said, the soldiers never truly got political, radical, or violent against the system. Which, by the way, is amazingly remarkable and says wonders to the German military discipline at the time. But on another note speaks to the fact that once they were back home, in the factory, on the farm, after the November Revolution had passed, they got the one thing they really wanted: Peace. They were relatively content with this. But this is one of a few pieces of this puzzle. Consistently when people discuss WWI and Weimar Germany they leave out (or simply don't know because it is really confusing) an outstandingly important key to history, one that shaped all political thought at the time, and that is that the war didn't end in 1918.

Here I refer to the paramilitary forces that were battling in Poland, Russia, Germany, and Austria. The Freikorps would be the most famous of all of these. Their vicious right-wing political orientation and bloody reputation for fighting Communists and protecting the Fatherland would eventually flow directly into the SA (Sturmabteilung) of Hitler's NSDAP and help back his attempted Putsch in 1923. Hitler attempting a coup in 1923 seems like a big deal, but he was coming in at the end of the paramilitary revolutionary era. In 1918 the Revolution in Germany began in Munich, then in Berlin, by Kurt Eisner (not only was he an advocate of communism but also he had a Jewish background). There was even a so-called Soviet Republic briefly established there. Then there is the Kapp-Putsch, the uprisings in the Ruhr afterwards, the attempted overthrows in "Red"-Saxony by communists too.

Basically what I am getting at here is that the average German going into the 1920s had based much of his or her understanding of the end of the war on conspiracy theories as to why the war happened. Then the entire system collapsed and after a very violent period going into 1923, with misinformation at every turn, the far Right would have the upper-hand and a HUGE advantage in exploiting this era; i.e. disenfranchising the Weimar Republic.

For example they manipulated the well accepted idea that "rich industrialists" had continued the war into an anti-semitic interprative model of understanding the war; another angle would be that the "leftist" government of the Weimar Republic (lumped up with "Bolshevik Jews") were part of this larger "industrialist" conspiracy and thus exploited the soldiers until they had the opportunity to take power: the so-called Stab-in-the-Back Myth.

The NSDAP was especially good at discrediting the Weimar Republic based on these claims, so as you might be able to tell where I am going with this: it wasn't necessarily a dissatifaction with democracy since they were voting for the NSDAP, rather a general suspicion of the Weimar Republic's founding, right-wing propoganda, andwant for a new direction come the Global Depression.

But STOP! This is only one side: What about the German COMMUNISTS! Everyone always dismisses them so easily because of the Nazis but they were making huge gains throughout Germany in the late 20s and at the same time as the NSDAP in the early 30s! They HATED the Weimar Republic too for very good reasons considering, from their perspective and rightfully so, the Weimar era was so anti-communist (thus anti-proletariat!) they were willing to tolerate cold-blooded murder, as was the case in the Ruhr and with Rosa Luxemburg Karl Liebknecht. Both the Kommunist Partei Deutschland (KPD) and the NSDAP were battling over seats in the Reichstag and each state's Landtag. The KPD also put out propoganda to distrust the Weimar Republic, to question its very legitimacy. Taken together (KPD and NSDP) you have the (more or less unless we into State populations) majority of Germans, now consider that both parties were attempting to delegitimize and dispose of the Weimar Republic based on historical precedence and communal experience over the past 10 years. Well...shucks, how exactly could the Weimar Republic make it through this era.

One last thing to say, if you go and listen to Hitler's speeches in the 1930s and read some propoganda in the early days he really lays into the fact that he defeated the Marxists in Germany (through great struggle), ended the Jewish plots (Weimar Republic, stab in the back, etc) and brought to a close the illegitimate Weimar Republic. Today we can get carried away into thinking that this means Germans despised the era of Democracy from 1919-1933, but in fact we are being warped by Nazi propoganda! Dictatorships tend to morph entire complex societies into the mould they want relatively easily and the Nazi dictatorship was remarkably efficient.

There was way more going on, I promise! In fact I had to simplify the hell out of this entire sysnopsis just so it could make some sense (I hope it did :) Also I wrote some pretty controversial stuff up there and am by no means "right", but you should be aware of the chaos that was German society right before the Weimar's end.

Sources:

Gerwarth, Robert, and John Horne. War in Peace: Paramilitary Violence in Europe after the Great War. Oxford: Oxford UP, 2012. Print.

Korzetz, Ingo. Die Freikorps in Der Weimarer Republik: Freiheitskämpfer Oder Landsknechthaufen ; Aufstellung, Einsatz Und Wesen Bayerischer Freikorps 1918 - 1920. Marburg: Tectum, 2009. Print.

Ziemann, Benjamin. War Experiences in Rural Germany: 1914-1923. Oxford: Berg, 2007. Print.

Germany pre-1945 had a romanticized vision of autocracy, not unlike what Russia had. The Prussian model of leadership which drove German politics prior to WW1 was heavily critical of Democracy, and not for lack of reason. Democracy has a tendency to be easily manipulated. Hitler's speeches between 1930-34 indicate that the German people were skeptical of absolute democracy. Hitler spoke about the "tumultuous waves" which would put one party and vision in power one year and the other the next, as a decadent result of Democracy. In times of crisis, people need and demand efficiency. Democracy doesn't provide for that. Germany pre-1945 is in a near constant state of growth and crisis.

There are actually a couple of reasons for that. On the one side you had those big problems which came with the loss of WW1 and the economic collapse of the german industry and all the reperations they had to pay. The Fascists and Communists were effectively using those circumstances in order to gain more influence among the people in the Weimar Republic. Many former Soldiers/Officers also said a democracy is a form of government which the Victorious Allied Powers in WW1 dictated over Germany and that being democratic is something ungerman. So many people were against Democracy in general because the politicians and their parties used the weaknesses of the Weimar Republic in order to further pursue their interests and to gain more popularity among the german people. Another reason for being unsatisfied is that specially in the years of 1930-1933 the time of the so called "Präsidialkabinette" was quite heavy for the people. Germanys Chancellor at the time of 1930 to 1932, Heinrich Brüning, even rolled back wage and and salaries in order to get the economy to stabilize.