They are hardline Marxist-Leninists, something that is very rare in the western world even amongst those who identify as leftist or socialist. If their views make you uncomfortable, then you’re not a ML, which is okay.
Left-wing politics is a very broad spectrum, and a lot of Lemmy users lean towards the more moderate end which brings them into conflict with the more radical communities that are Lemmygrad and Hexbear.