What's with people who AFK mid-match?
Not the trolls, but the people who're like "Oh I went to the store" or "Oh I picked my kid up" midway through a ranked match? It sounds heartless, yeah, but they're wasting all of 9/4 peoples' time because... well, "it can wait until it can't", and then they get surprised when the rest of the team asks them why the hell they couldn't learn to prioritize tasks instead of try to sneak one League match in there and basically ruin it for the rest of everyone else.
I get it - things come up, but this isn't that. This is just "Ah, crap, I need to go to the store. It closes soon!"