That's something developers Riot Games are trying to address, and according to lead producer Travis George in an interview with Gamasutra, there's a novel way they're going about it.
"We actually have built a team around this, to address [the problem]," he says. "We call it, lovingly, the PB&J Team, which stands for Player Behavior and Justice Team. And there's a lot of really talented folks on that team, including two PhDs. One's a cognitive neuroscientist and one's a behavioral psychologist."
"We've actually developed specific trends, and our own set of metrics that we look at for measuring what percentage of times we think that players will encounter a negative experience in a game, and how severe that negative experience is," George continues. "And then we have to build things or be responsive or message the community in a particular way to address those things."
"This is going to be a major focus for us".
Good to hear. Lord knows the game needs it.