Jason, I think a question that's really in need of asking is whether the trolling actually bothered Tim. I don't think it did. In fact, I think he might have enjoyed it. He seems to get off on conflict and a "me versus the world" sort of attitude. Tim doesn't necessarily want to be treated the way you or someone else would want to be treated, so it's tricky to project your own standards onto him.
And of course the friendliness here is "selective". It IS the default, though, and you don't have to do a thing to earn it except not be a troublemaker, in which case, yeah, you might have a problem eliciting friendliness! Tim made his own bed here and was given every opportunity to fix it.
I guess I'm confused about what it is you're driving at here. Are you saying that Ethan (et al) bear responsibility for Tim's behavior on the forum that led to him being banned? Maybe you could clarify that?
I do think it's interesting that "the forum" tends to be held responsible every time somebody leaves or is banned. Personally I find THAT trend a lot more disturbing than people leaving. The forum can't be blamed for every individual's bad behavior, weird standards, or thin skins. There hasn't been a single dramatic departure that hasn't made me say "wht da?" They made the decision, and in literally every case while "hot" and without doing anything to actually seek resolution or work things out. Why is the responsibility never on them?
I also find this meme (mostly on Facebook) that the forum is somehow intimidating or hostile or insular to be endlessly bizarre. This is one of the friendliest forums I've ever seen.