so nobody feels ‘trapped’ in an unfun game.

I think this is an understated problem. It’s simply awful to be in a slowly losing multiplayer game that you feel you have no control over, and when you also simultaneously feel that you aren’t playing with people you care about. It’s pretty easy to start not caring about monitoring your behavior. After all, who cares if everyone in this lobby thinks you’re annoying or awful to deal with, you will never see them again, and if you do they won’t recognize you, so act out your frustration without fear of real consequences. I also don’t think bans for “bad behavior” actually address the reason people behave this way, it just encourages them to hide it in more subtle ways that automated scripts can’t detect, or that give them some plausible deniability.