Please Riot, ban people for Int Feeding

So I just logged on to do some draft mode for the night. I was doing something off meta, syndra support, and I hover my champ. The guys below me bans her and tells me he isn't going to let me play her. I say that's a jerk move and move on. I figure I will do another damage support like lux or vel. No issue, move one, whatever. Then the guy above me takes his champ. So he says he is gonna int feed. and then he does so through the entire game. I just don't get it. Why do people like this deserve to ruin the game for everyone else? We could have had a perfectly fun game, but no. This like this make me want to quit league.

I know this happens to everyone, but how do you guys deal with it? (Also I have screen shots of him saying such, but I dunno how to attach them)