There is a very strong correlation between the level of resistance and the harshness of the occupation. If you find yourself in an occupied country but get treated "well" your motivation to resist is likely limited. What does the single person have to gain from resisting? If you are a non-jew, with family, for example in France during the occupation you have a lot to loose if you decide to fight against the occupation. The situation for a Polish person is often vastly different, especially for jews which were a big part of the Polish population at this time. While there are a lot of things to consider if you want to understand the motivation of a resistance fighter, this is the main factor. What does he gain, what can he possibly lose? The will to resist is often moslty attributed to character and patriotism, countries take pride in their resistance movement and romanticise it. People from Poland for example are rightfully proud of this part of their history, when they kept fighting against the odds but it should be remembered that they were in a vastly different situation than France, Norway and the Low Countries. While you singled out Poland for a country with a big resistance movement there were many areas with major partisan activity. Belarus and Ukraine were areas with strong partisan actions, working tightly together with the Red Army. Several hundred thousand of these partisans died during the war. Many joined the Red Army when their territory was liberated and moved towards Berlin as regular soldiers. Yugoslavia had also a strong resistance movement. All those countries have one thing in common which seperates them from the other countries: extremely harsh brutal occupation. At the end of the day if they are searching for you trying to exterminate your family and you can't hide because they are everywhere you may just grab a gun and fight. If you are sitting on a farm in France with three kids you may just sit tight and keep your mouth shut.

Obviously the German attitude towards Poles was different than to France. Poles and all eastern people for that matter were mostly Slaves which were regarded as Untermenschen. Negotiate with Slaves or work with them wasn't planned they were to be exterminated. Well organized countries act mostly oppertune, Germany/Hitler did not. Racial ideology stood often above war effort which made collaborating with Germany nearly impossible. This obviously brings us back to the general situation of a Polish resistance fighter, his option were bleak and limited.