their users deny genocides

If you are referring to the Xinjiang issue, then it just reaffirms what @davel@lemmy.ml just said:

it’s largely because the Anglosphere has been indoctrinated against real, actual socialism their entire lives

Because the "Uyghur genocide" in Xinjiang is another example of propaganda. Or do you really think the West cares about Muslims and want to protect their "freedom"?

call everyone that has a less extreme left opinion of politics Nazis

I don't see anyone in Lemmygrad calling other people "Nazis" because they disagree with someone in a discussion. I usually see them criticizing others as "liberals." This is either a misrepresentation of leftists in general, very common among conservatives, or you are frequently being called a Nazi. I don't know, maybe that's on you? 🤔

end up being so “anti-racism” that they’re racists themselves and take all critics as personal attacks

That's so specific you should give at least one example of this. We have very strict moderation against any bigotry, so I challenge you to link any "racist" attitude or comment you have seen in Lemmygrad. I will give you 24 hours, and if you don't reply with an example, I will edit this comment saying you chickened out.

EDIT: They chickened out, as expected.