It's a natural enough thing to do, and not for some misguided reason of moral equivalence.
The striking thing about Nazi Germany is that it happened, and that people not too different than us let it happen. If your interest in studying this stuff is thinking about how we all keep it from happening again, studying comparable events - especially ones that happened right here - is potentially important. I could elaborate but it really feels like I'm just stating the obvious.
But it isn't natural when the comment is based a misguided moral equivalence. And my point is that they are not comparable. It is as bad as if someone posted a story on Manzanar, and someone replied "Kind of like when my parents made go to sleepaway camp." That would be an insulting to the Japanese internees.
The striking thing about Nazi Germany is that it happened, and that people not too different than us let it happen. If your interest in studying this stuff is thinking about how we all keep it from happening again, studying comparable events - especially ones that happened right here - is potentially important. I could elaborate but it really feels like I'm just stating the obvious.