Why do people play to troll?

And more importantly, why isn't it punished?

This duo of Kat and Rammus trolled us the entire game, from champ select on with Rammus instalocking when someone else wanted the role. Then just spamming "lololol nerds who cares about a game lolol". Made our Nunu and Vayne tilt so hard (vayne was just pretty bad too though). But instead of punishing the trolling duo that caused out team to tilt, rito is probably going to throw a chat ban on Nunu. It's really really dumb. I know you're going to say, "someone else's behavior doesn't effect yours", but A, kind of does...and B, if they weren't in this game trolling, our Nunu or Vayne wouldn't have tilted. It's really common sense. So this duo is just going to get into another game to troll it and cause more people to flame and get punished. This is what I'm saying. There have been 0 improvements made in the "toxicity" of the community. Why? Because they just slap people like Nunu "ragers" and "toxic" (which you could just mute anyway if it bothers you that much) and let the cause of it go. Until they actually start to address the cause "toxicity" in this game, there aren't going to be improvements. As made evident by the current situation. I'm not sure how Lyte, and this overly sensitive community that rushes to defend these trolls with their "omg he might have been trolling but you were still MEAN to him", can't see this. There's normals and there's ranked for a reason. Don't play ranked if you are just trolling around trying to get people mad. You don't want to fix the issues that cause flame in the game, that's fine. But then don't bitch about how "toxic" it is, because it obviously isn't working.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2064052398/230832192?tab=overview