Willfully and gleefully helping to destroy people's lives. My brain normally just shuts down at such a level of awfulness, which means it's probably worth trying to understand, at least at the intellectual level.
I mean, is this just straight up sadism? Is the guy just happy ruining stuff, a child knocking over blocks, except that he's in a grown man's body? Doesn't seem implausible, but I don't feel like I understand it any better.
Is it the money? A cold calculation? But he seems to be so happy about everything, and frankly, not bright enough for that. "I have nerds for days... I have nerds on nerds." Really?
Is he one of those that just can't back down from an argument? The article mentions he was recently in a physical fight. Maybe he did something jerky a long time ago, someone called him out on his jerkyness, and so he doubled down, was even jerkier, just to show that other guy. He did that a couple of times, just to prove he couldn't be called out on stuff and it became a habit. Now he's wired to seek out stuff that other people will react poorly to, because in some portion of his brain it translates to him winning an argument.
I like that third explanation the best, because there are parts of the behavior I can relate to. I can sort of understand how it could happen. But this guy is so far out there, I just have no idea. My own emotions are probably a really crappy guide for figuring out how that guy ticks.