The scariest thing about Nazis is that they're human and even pretty smart sometimes. To reiterate what others are saying: dehumanization leaves you in a blind spot for the humans around you who can silently undergo vast transformations from people you thought you loved into Nazis. They throw away their humanity yes, but they had to be human to throw it away. Dehumanization is also how the process of becoming a Nazi starts. Don't even mirror it in jest, try on radical empathy and face the truth: humans are horrifically complex. Nazis are unfortunately humans.
Nazis are incredibly mechanical honestly. They lose empathy and then others become mearly disposable objects. You might commit murder just like you would throw away a plastic bag. There is a totally absence of care which leads you to inflict terrible things to others.
I also doubt how many actual Nazis there are. It is often thrown around which leads it to lose the horrible meaning. I've seen people shout Nazis over much less deadly things. Don't confuse systematic mass murder with someone having a questionable character. They can be a terrible human but they haven't committed the level of crimes as mass murder of millions. The level of death and suffering caused by the holocaust is not a joke and certainty not something to use when your upset.
Sorry for the rant I just needed to get that off my chest. I'm not really addressing anyone in particular.
Justifying the murder of someone by dehumanizing them is exactly what the nazis did. It's what Israel is doing in Gaza, etc., calling everyone Hamas and dehumanizing them. Nazis may be terrible people who need to be fought against and whose ideology needs to be stopped, but it's never good to start dehumanizing groups of people over any criteria. All that said I love playing Wolfenstein and Indiana Jones games and killing hordes of nazis.