Most instances also defederated from lemmygrad (commies) so its not generally politically left either.
IMO, Stalinists aren't exactly tolerant either. You're still talking about a totalitarian and authoritarian viewpoint, even if they're on the left on economic matters.
IMO, if your point is to make a community welcoming, then you have to get rid of intolerant voices. That--broadly speaking--means that you have to remove people advocating for any kind of absolutist, authoritarian rules. It's easy to see at a macro level, but it's all fuzzy at a micro level.