I think we probably share the same opinion so I'm just going to have a look at what the guy that you're talking about said.
There is ALWAYS a choice. My Grandfather snuck out of Germany and refused to work for Nazis. If you work for Nazis, you are a Nazi. Thank you grandfather for being brave and not caving to the Nazis. Shame on anyone who caved. f*ck the Nazis...including this weak pilot.
OK the first sentence is quite an interesting one, he later contradicts this of course.
There is ALWAYS a choice.
Of course there is always a choice, but not all choices are created equal. A person in a free and democratic society would almost certainly choose to never associate with the NAZI regime, but because the regime was a fascist one the people had very little choice but to work for or with the NAZI party. This, coupled with the state propaganda that was forced down the throats of everyone in the nation, but especially the young, means that the choice to be a NAZI was a black and white choice between being a NAZI, and being a revolutionary. Many people didn't want to be a revolutionary for fear of being punished by death and most of them would have been almost completely ignorant of the massive human rights abuses that were being perpetrated on their doorsteps.
My Grandfather snuck out of Germany and refused to work for Nazis.
Bully for him. Did he sneak out because he felt morally obliged to do so, or because it was in his interest to do so? He clearly didn't think the regime was so repugnant as to merit fighting against it, so it could even be argued that by the same logic that this guy shows his Grandfather is almost tacitly supporting the NAZIs by not standing and fighting back against them.
And of course, the very fact that he had to sneak out of the country should tell you that this wasn't a decision to be taken lightly. He also didn't mention any of the rest of his family going with his Grandfather so I'll assume that his Grandfather acted alone. In which case he was in a very different situation to many people in the country who had families to think of. For many the decision to run away was not a plausible one because of the inability to coordinate such an escape between family members, and the fear that said family members would be punished for their actions by the police -- especially in a time of war.
It would also be interesting to note whether or not this guy's Grandfather ever formed a part of the bloc which swept the NAZIs into positions of power in Germany before the war...
If you work for Nazis, you are a Nazi.
That doesn't follow in any logical manner whatsoever. If I were to work for a school run by a local council I would not necessarily have to belong to the ruling party in that area, or think that any of their views are right. In the same way, a conscript (because that's what the majority of them were) to the NAZI air force or army does not have to be of a NAZI persuasion in order to serve. These people were all tiny actors in a big conflict who were almost completely unaware of anything beyond the activities of their own unit or battalion -- so to hold them responsible for any acts but their own is impossibly unfair.
Thank you grandfather for being brave and not caving to the Nazis. Shame on anyone who caved. f*ck the Nazis...including this weak pilot.
If you accept what the guy says earlier, that "there is ALWAYS a choice", then this is a contradiction. In my opinion in order to use someone's choices against them you first have to demonstrate that they were freely able to make that choice (that is a tenet of criminal law too). So if you later use the term "caving [in]" you are contradicting yourself in a way because you are accepting that the people's ability to make a choice was compromised by the weight of state pressure and propaganda. I do not conscience personal attacks based on what somebody did under duress, because what somebody does when under severe pressure is more often than not a poor reflection of their overall personality. And of course, we haven't even discussed the NAZI propaganda that put further pressure on the German people by systematically misling them.
Finally, I would argue that the pilot made a much braver choice than this man's Grandfather -- in choosing to end his life rather than go on serving in the air force of the regime he had to make a much more difficult choice than just choosing whether or not to run away.
There was also one other bit of your post that got me thinking, so I'll quote that too.
But I really have trouble settling the argument in my head about whether or not a whole population should be blamed for not defying a violent regime. Is that fair? I don't think so, but why?
Firstly, it's important to note that except in abstract terms you can't refer to a whole population as one entity, because populations are made up of masses of individuals who are acting in their own interests (as we all do) and who therefore have their own biases and problems to deal with.
It's also contextually important to note that many people were not fully aware of how violent and oppressive the regime was until after the war had ended. Hitler was not a military dictator who seized power following a coup, he was a democratically elected man who managed to weasel himself into the top job through clever political manoeuvring as well as intimidation. The NAZI regime itself was oppressive but was not as violent as many regimes that have been seen since. Dissent can easily be clamped down upon as long as you have the army and police on your side -- and since both had to declare a personal allegiance to Hitler himself there was not much danger of them switching sides in any great numbers. I personally cannot think of many (any?) times in history where reform in a totalitarian state has been driven by the people from the bottom up, at least not without the support of the military or some government officials in reasonably influential positions -- because it is just not a feasible thing to ask for. Public demonstrations are effectively just raging against the dying of the light, or pissing in the wind, depending on how poetic you feel, because without any support or sympathy from higher-ups such demonstrations can simply be crushed at will (Tiananmen Square would be a good example of this).
Sociologically you raise a very interesting topic though which I'll attempt to discuss. Have you ever been in a situation where you are walking down a busy street and see an old man with a bleeding nose slumped on the floor having just been mugged? Statistically people are far less likely to help in a situation such as this than when they are on their own walking past the same gentleman. We tend to assume that other people are more qualified to help than us, and normally when someone else steps in to take control of the situation we are eager to help because they have abdicated us of the responsibility that comes with having to take charge of such a situation. In that respect the refusal to defy an oppressive regime is simply the bystander effect writ large, as people in NAZI Germany may have noticed the abuses of power but may have felt that any attempt at intervention on their part would be futile and would just harm them and others around them.
The case of NAZI Germany is also a probably example of pluralistic ignorance -- where the population as a whole may be privately in opposition to the regime and its policies, but may be conscious of the fact that there is no apparent opposition shown by people around them. They may put this lack of public opposition down to a genuine support for the regime rather than fear and thus refuse to voice their own opposition, causing others to not voice their own views, and thus causing the whole community to spiral into an almost self-destructive process of constant inaction for fear of being different to the imagined norm. This is hypothesised as being one of the main reasons why opposition in the USSR was so low under communism, and I have no reason to think that it wouldn't also be a problem in NAZI Germany, a remarkably similar state in many ways to the old Soviet Union (at least in the terms of how dissidents were dealt with, and how power was maintained by the ruling elite).
NB: I've gone back through the post because I made a couple of errors in grammatical terms, hopefully I got them all...