"No offense to Mr Turtledove, I don't think he's a neonazi [...]"

He's a Jew, I think how his message at this particular book comes across is rather induced by his presumption that everyone embraced the idea of the Holocaust 100%.
What I mean is that this whole thing must - to him personally - be much more burned into his mind, and he might assume that everyone is on the same level that he is on.
That's why he does not really bother mention things commited by Germans before surrender, which might would have balanced the book out a bit more.