What I took away from the book was that all these people were very eager to say variants of 'das haben wir nicht gewusst' when at the same time they also describe how the jews were systematically removed from their society and every part of civil society was taken over by the nazi's.

I would add to your statement that almost everyone should read it. It's unnerving to read how 'normal' all these people were in some way and how 'easily' it all happened because the population generally disliked jews.