Folks, these are just the facts. There have been whole studies about this where decades after the fact folks have interviewed German Nazis and found that they felt no remorse for what they'd done, and didn't even see it was wrong.
Once you've hit the point that your only solution is kill, imprison, or enslave anyone who doesn't agree with you, you're very much beyond being talked off the ledge. That's the history. You don't HAVE to like it. It's how fascism works.