wow isnt a true mmo tho, if it were it'd have been dead a very long time ago now.
I think I see the disconnect here. You haven't played Overwatch in the last couple of years, have you? The Overwatch player rating system I mentioned doesn't have downvotes. There's no way to malign fellow players with bad ratings. Players can still be reported and investigated for particular behaviors outside of the rating system (I don't know if such reports affect ratings), but those reports are handled on a case-by-case basis, rather than automated like the upvote system. Which is more than I can say for WoW and its mass abusable afk-reporting, for which 39s gained a reputation years ago.
A non-downvote rating system may still create player sediment layers as @Selaya warned, but Overwatch's system doesn't give players a stick with which to beat other players.
easy solution: do. not. pug.for all the garbage overwatch is, it's report/silence system actually works, unlike some games (R.I.P. Heroes of the Storm)