There's almost always rage, even when ur on the winning team. I have a few games where nobody rages, and ppl just accept the other team is better.
Usually, after ten minutes one guy blames a teammate, and goes /all my team sucks. Personally i only think it's fair to blame yourself. There are exceptions ofcourse. If someone mid/late game is pushing a lane solo and gets killed 4 - 5 times, without destrying a single tower, it pisses me off.
If the team advices him NOT to do that after the second time he dies, but the stubborn guy keeps on pushing alone, he's making it hard not to rage.
In very rare cases i hear the losing team say they lost to a better opponnent. Mostly you get the rage in /all.
But, thats why u have the ignore list. I hate to be in that game, with 5 aggressive tryhard enemies. They push, destroy 2 towers in all 3 lanes within minutes, and keep pushing on. Then, someone in our team decides to blame 1 (one!) person for getting pushed back in 3 lanes. How stupid can u be? But is the rage growing stronger? I don't think so, as the community grows, more ppl come, so the chance u have an ass on ur team also gets bigger.
Then, i hate que dodging ppl. It's the most annoying excuse that MM is not working correctly. No, i dont want (insert champ name) on my team cause it's a guaranteed loss! rubbish!
I have ten leaves on my account, but never que dodged. Even if i get a kat and mundo in my team with clarity and revive, i just play. The only times i can justify que dodging, is when u get an unexpected phone call/visitor/anything like that and know u can't finish the game. Then it's better to go, instead of leaving after 15 minutes of play.