Thank you for saying this in a more detailed way than I have been. This is exactly right. They built their own leftist haven and became a whole culture of their own, and then became federated. There is bound to be an initial clash, but honestly I think most of the people who hate on them never gave them a chance. All they saw were the shitposts and the in-jokes and you closed the door.
When it comes to dealing with HB users here, my advice is the exact same as dealing with other users
if you don't like what someone is saying (because it's idiotic, obstrusive, or whatever), block the person for some peace of mind.
if you're consistently uninterested on the content coming from an instance, block the instance.
I see a lot of leftists (and leaning leftists), even on .world, who would be better off interacting with the users there (maybe blocking the shitposting comms). And outside of those most-seen comms (chapotraphouse and dunk_tank), there is genuine conversation and less shit talking and in-jokes. I believe, with more instances coming in that are federated with them (mine, .ml, and lem.ee? are a couple), some of the Hex-natives are understanding how to interact with curious left-leaning people with unintentionally wrong-headed ideas.
Downvote me all you want, I stand by Hexbear. o7
I did my job. The democrats had one job too, and they failed.