Literally no other game on earth makes me mad accept league. When I lose a game because of team mates or me feeding or whatever it just pisses me off so much. especially when an enemy champion is so fed they can kill you before you even have a chance to react. Why is this game so frustrating?
Several reasons:
You're stuck in that game. Whereas in a game like CoD or otherwise you can just leave that lobby and find a new on, you're stuck there with your loss or your raging teammates or....well you get the point.
It's momentum based. In other words, doing badly at the beginning decreases your chance of doing well later game and therefore makes it even harder to win overall. So where some games you can shrug off an early mistake and jump right back into it every mistake you make has a lasting impact.
The competitive element is huge in this game. Whether it's people practicing for ranked or just someone looking for a first win, winning matters more than similar games. Combine that with a the naturally high tension moments (dodging skillshots, farming, etc.), and you get a perfect storm for emotional outbursts.
Lack of sportsmanship. There are several contributing factors here, but I believe the biggest one is the fact that the core audience for league are not ones to spend much time in another sport. So having the idea of sportsmanship ground into their heads is simply not there. Combine that with the stereotype of gamers being whiny 5-year olds and you don't have an environment that reinforces being respectful to each other. In fact you have an environment that reinforces the exact opposite.
People tend to binge play League. This can be said for a lot of games as well, but after enough intense games (which all League games, in comparison, are) people tend to have their tempers worn down. Especially if people don't drink water or eat after a while. And let's be honest here folks....how often have you not noticed how thirsty or hungry you were after a few games??
There are plenty more but that's off the top of my head.
