if you'll pardon me complaining about this publicly: some of the meanest mfs i've met online are internet-poisoned communists. If i weren't already a marxist-leninist, i would have some very unsavory ideas about what communists are like.
Lemmygrad and Hexbear are very nice places, thank you comrades ^_^ … but elsewhere, even IRL, i've met incredibly rude people calling themselves communists and i need to stress this: if you want people on our side, you need to give good impressions of what we're like. Don't be hostile or dismissive or just violently anti-social. If you have to explain something for the millionth time to yet another liberal or anarchist… do it [insert Sankara quote], or at least find a nice way of saying you don't want to. Save your offensive capabilities for people who deserve it. And please, PLEASE, go outside occasionally. IRL interaction is healthy, and will quickly kill any terminally online behaviours you might have. Maybe join an org while you're at it ;)
i'll stop stating the obvious now. Have a great day, comrades.
I couldn't give you a definite answer but I have a quirky little theory of how the users there got to be that way. It's important to realize that most Marxist learning groups don't sprout from a place of everyone being given the same authority. Like Mao wrote, "NO INVESTIGATION, NO RIGHT TO SPEAK." /r/communism101 on the other hand has no such barrier to opinion and so revisionism and flawed analyses are abundant. There is nothing keeping this in check because the mods are absent at best and unprincipled at worst. It's essentially a breeding ground for debatebros.
The life cycle of a /r/communism101 debatebro goes something like this:
A promising socialist in the process of unlearning liberalism goes to /r/communism101 to get their questions about Capital answered.
They get their questions answered with likely revisionist perspectives and skewed applications of dialectics by flawed but well meaning comrades.
They lurk on the subreddit for a while until eventually they feel confident enough to carry on the game of telephone that is the amorphous ideology of /r/communism101. At this point their liberalism has likely not been filtered out yet, ideological purity, moral superiority, and an inability to receive critique are common traits found in a /r/communism101 debatebro. These traits inspire the toxicity you find in that community.