I believe this is a lasting effect of the PR campaign to vilify Hitler and the Nazis. Don’t get me wrong, Hitler and the Nazis are obviously villains and deserve every ounce of contempt. But the US went to extra efforts to make sure people knew it was the work on Hitler and the Nazis and not the Germans so that we could quickly forgive the Germans and make them an ally.

Fun fact, before Hitler, the worst person euphemistically was the biblical Pharaoh

Edit: getting some down votes. I hope it’s clear that I’m still trying to say that hitler was maximally bad and not trying to reduce anything to that effect.