Toxicity

Why is it that whenever people generally enjoy a match and win they flame anyone teammates included? You would think the proper way to go about making the game better is to help other players fix where they messed up.. For some reason they think its just fine to excessively talk down to, berate and belittle people because said person doesnt play the way the Rage monster wants. Anyone know if they are going to do something about the levels of Toxicity in games? Those type of people are just a mood killer.