The people who rage at you with "stop feeding" or "this guy is inting" tend to forget that every game in LoL has one winner, and one loser.
If you win a game in twenty minutes flat, chances are, you stomped the living daylights out of the enemy team.
Does that mean they inted? Hell no. They got their asses handed to them on a silver platter. Then for good measure the silver platter was smashed over their head.
But, then when the reverse happens, and you lose a game in twenty minutes, several people per lobby tend to start hurling the "feeding" insults. You gotta lose some time, and no matter how good you are, you're bound to get games where you're double or triple negative.
Leave people alone. They're not inting most of the time. There has to be a winner, and there has to be a loser. 50/50 chance either way, no matter what.