I don't know if it's worth checking into whether or not he's bought STEEM and powered up, but he does have over 7,000 SP, so it's coming from somewhere, and I'm not aware of anyone who has amassed that amount of SP since January, so something's going on. I've seen reps going pretty high in short periods of time thanks to bidbots. SP, not so much, but maybe the other folks I've stumbled upon weren't powering up their earnings.
At any rate, as long as the illusion exists, people are going to do it. And if they actually are making some healthy earnings, they're not going to quit. However he gets those upvotes and comments, they really look impressive to the untrained eye. Annoying to the rest.
Just looked more closely. He's been powering down, too, so there's a couple of thousand STEEM sitting there. Wallet history doesn't go back far enough for much of anything else, other than the bot transactions and his earnings.
If a few people withhold their vote or flag him then he loses his profit even if he still gets more rep. This platform gives us freedom to do what we want, but the community can still police it. Many are dealing with some of the smaller abuse, but they are scared to tackle the big fish.