Why are the communities of competitive games so notoriously toxic? Culture. I think books could be written about the 'cultures' of certain games, but basically, the culture of competitive games places too much value on rank and prowess. And this has a few consequences.
People react to this cultural pressure in different ways. The way we see this most often is people throwing temper tantrums at teammates for poor performances - the logical end-result if someone's worth is largely based off of how well they play. Or maybe they feel cheated of a rank, or number, because the matchmaker put them with someone who they consider lesser. This is a direct insult to them - seeing the game subtract from what literally defines their worth because of someone else feels awful.
This is where what I call de-'sweating' comes in. It doesn't seem to me that there is competition for the thrill of it anymore, but merely to dunk on the other dude across the screen. I don't know realistically how this happens, but the emphasis needs to move, or we get situations where kids sling racial slurs at each other because they couldn't win, and taking that therefore as an insult to their self-worth. Or burning themselves out at age 19 playing 9 hours a day trying to improve to a certain level, so they feel better about themselves.
Ladder anxiety is another common manifestation of this. But that's not the main concern, which is that the laser focus within these communities on your ability to play the game well, and not on competition itself or sportsmanship, fosters the awful environment within these games. De-'sweating' just means rank doesn't matter. It should be a tool for fostering fair competition and even play.
lunchtime text dump over
I spent a lot of hours hanging out on the landing platform of the Bespin map watching duels or fighting them. I don't even think I ever got even a little bit good at that game, but the server/community I was with was my formative internet experience. I fukken knew everybody on that server (and on our BBCode forum), compared to today where in every game I play the avatars come and go and I can barely tell one apart from the other. It's like when you read people predicting what the internet will be in the nineties and compare it to how it actually turned out - communities separated only by communication at the speed of light, or individuals separated from each other by an algorithm-based barrier.