You forgot a scenario:

You enter an instance, perform adequately and are then 'mysteriously' kicked because someone doesn't like your numbers. This becomes the standard procedure of all those 'git gud' folk out there. [After all, if you can't 'git gud' why should you be tolerated in the instance?] It's not reportable, because nothing has been said. It becomes so prevalent, however, that subscriptions start dropping rapidly because the folks who get constantly kicked go find another MMO to play.

Congratulations! Toxicity has been avoided!