For some time now I've been enjoying a very old board game called Go. For those of you that don't know it, it's the asian, 4000 years old equivalent of chess. It's a game in which skill is, obviously, the only way to victory. There's no luck, no adventage, just willpower and skill.
One of the aspects I like from Go is that, being such a traditional game, the rules of courtesy have evolved to the point they reflect, in my opinion, how etiquette should be in every competitive game. If you read the code of conduct for Go, you'll realize how logical everything is.
It is legal to surrender in Go. Not only that, it's considered very honorable. In fact, it isn't considered polite to keep on playing when your defeat is evident, because you're wasting your time and your opponent's. This may not be directly applicable to a videogame in which fun primes over winning or losing, but I'm not willing to go that far.
What I'm trying to say is that you should not, by any means, be forced to stand the humilliating boredom of being steamrolled. 10 people play a game of LoL. Four absolutely don't want to play any more, and they happen to be on a single team. From that moment on, it makes absolutely no sense to keep on playing.
I feel sorry for those who can't stand their opponents leaving before breaking the nexus, but stop for a second and think what would happen if those four players simply refused to play. You would be playing an absurd PVE minigame. The problem is that, if you keep those players from surrendering, it's even worse, because it's not only trivial for the attackers, but horribly boring for the defenders.
I won't even go into what happens when the attacking team decides to go duck hunting and forget to push. This is humilliating, Riot. Sometimes you need to surrender because the other team is not playing to win, but to screw with you.
I just read Zileas confirming they will be introducing measures to punish surrenders. This must not happen, Riot, it goes against all logic and will bring frustration for many, in exchange of satisfaction for very few. Surrender feature is completely logical and should stay as is. If anything, make IP and XP rewards be proportional to game time, but don't step out of the linear relation.
Those are my two cents. Hope it helps.