There are many reasons why people leave:
* they hate the team comp and think they will lose
* they may need to go to grandma
* they may need to go to the toilet
* they get angry and rage quit, or just generally go afk to make you lose
all of these shouldnt be allowed. you dont know if you will lose with your team comp, you should have planned your time better if you meet up with grandma, you can go to the toilet before a game, its just 30 min, we dont care if youre mad when your team is behind, keep playing AND KEEP TRYING.
There are a few reasons though, where it should be allowed to leave, and the last one of them I would like to discuss:
* Theres litterally a god damn fire in your house, a robbery or something else crazy, yes, go ahead and leave your god damn computer RIGHT NOW
* Your internet broke down, well, you dont want that, but you cant help it, just sucks that its hard for riot to detect that
* Game is buggy and won't let you reconnect. Also sucks, riot can't really detect it.
* Your team is flaming you.
So why should you be allowed to leave when your team is flaming? Imagine you are not in front of your computer, and outside playing basketball with some people. Those people start insulting you, saying stuff like "You ***** *** * ** **************** * ** ******* ******* ******** * *********". What would you do? Stay on the basketball field and keep playing with those nice people, or just %%%%ing leave? I'd guess you would leave. And you know what, no one would say anything bad about you simply leaving the game. So what if they can't properely play their basketball anymore? They shouldn't have insulted you like that, mentally harming you. It's your right to go away from those people.
Ok but, you now may say, "just mute them". Yeah sure, I can mute them, and I wont hear their shit anymore. But that's kinda not why Im playing this game. The reason why I play games, specifically multiplayer games, is so that I can play together along with other humans and have a good time with them. If I cant hear anything they say, that's kinda ruining it for me. Also because of the now missing communication, the game is made much harder for me. Obviously in a game like League, you rely on communication.. And often times, when they were flaming, they also intentionally feed you, like not helping you in teamfights etc. Basically youre gonna have a shit time and likely lose the game ("toxic people lose 23% more games... blabla"). <-- This is riot games confirming it in the game loading screen (i dont know the exact percentage but its something like that). I shouldnt be forced to play a game where I know everyone hates me and doesn't wanna play with me, intentionally letting me die and fall back heavily. Its a horrible experience. Why am I forced to stay?