Michael precisely said it as it is...

What Bible said: let it throw first stone one who didn't make any sin... something like that, I didn't tell it precisely, but you got the point...

Just think would you reject job offered by your government. And would you think it that situation "My government is evil (if it is), I will reject offered job"

Like Mafia, they give you an offer you can't refuse...

I don't know was she Nazi or not, but, she got the oportunity to do what she like (make movies and photographs), government secured her budget, and else, by that working she had oportunity to establish herself as world recognized artist, etc... Not many people would reject that offer. And if you know that offer come from somebody (in this case dictatorship government or dictator himself) for whom you know that lots of bad things can happen if you insult them by rejecting (like stopping you to work, kill you, kill your familly or/and friends, remember that was Nazy government in 1930es/40es, who would say anything if some artist dissapear...), then...

Being suporter of that government or not, rejecting that offer would be dangerous, and than, it would be rejecting of many oportunities. And people sold themselves for much less...

Look what happens these days with Nobel price receiver, Gunter Grass...

Today there are countries which rest of the world don't like, even hate. But, people in those countries don't think they do anything wrong if they work for governments of those countries, and don't pay much attention what rest of the world think. Leni did the same 70 years ago...