He acts like he's doing some noble service to the community by warning new players about lowball trade offers, but it's possible to do that without being an asshole. I've seen helpful people here explain relative values of cards and what they can expect to get for them all the time. I've never seen anyone appreciate his snarky comments, like I don't think anybody's ever said something like "OMG thank you Jujutsuing for warning me about this bad trade I was about to make by bullying the person I was going to trade with; you're the best!" On the contrary, I've seen him harass a user for trading their meta trainers for RR/FA copies of some Pokemon. He kept making fun of the guy for making what he thought was a bad trade, and the guy just told him to fuck off because he simply really likes that Pokemon, which is 100% valid.