So I'd also like to give my two cents on the matter, but excuse me if this sounds more like I'm talking about myself as opposed to Mystic and his ilk.
Back in the day, I was a lot like this kinds of jerks. Shitting on kids and their "awful" projects, being toxic and outright abrasive to others; even my own friends, but especially newcomers. Couple that with me being a teenager and then you also have "edgy" """humor""" in there too. I even made a whole Youtube series about making fun of awful Sonic-related videos, of which I have completely purged by now.
I was brought up in a pretty nasty way by the communities I used to frequent, but the old IRC channel, #srb2fun, was the place I spent the most of my time, and the place where I was influenced the most. I was heavily molded by Mystic and the others of the community at the time, and in turn, I shaped others into that mentality as well (or at least the ones that bothered to stick around). It was a very "Jerk or be Jerked" kinda place, but we'd also be jerks to eachother, so either you had the ironskin to handle it, or you just pretend that you do, which is what I imagine most of us did.
I'm... not quite sure how it happened, maybe it was just gradual, but I've eventually stopped being as nearly as much of the ass that I used to be. I've come to look back and regret a lot of the things I said. I've tried apologizing to some of the people I've hurt years ago. I've cleared out a lot of the old "edgy" content I used to make. At some point, I did grow up and take responsibility, and now, after all those jokes in IRC on how "I should totally be judge", now I'm a moderator.