I think these are two different things that should be separated. Ranked games with matchmaking and hats/achievements. One can exist without the other and they pull in people for different reasons. For example most of newgrounds has achievements / hats / whatever, but no multiplayer at all. On the other hand hearthstone has ranked games but very little to do with hats (there are paid and collecting elements, but they actually affect your play - they're not useless tokens). Then there's Dota with both.

> "giving up" is as easy as a keystroke

Kids often rage-quit games and interactions in real life games. Not sure if it's that different from this point of view.