Reading all this controversy over poor behavior really surprised me. I have played online games on and off in a highly casual fashion for about two decades now - the quake series, counter-strike since the beta days, starcraft 1/2, warcraft 3, etc. - and I have always seen these antics as mostly miniscule and harmless.
Someone writes hateful/immature messages in the chat? Ignore them. Someone's audio-spamming the voice chat with their stupid music? Mute them. I mute voice chats by default these days because I am not interested in hearing other peoples' voices when I'm immersed in a game. I rarely use the chat, often removing it from my HUD altogether. It's a distraction and I think it gets in the way of the gameplay.
Are we so easily offended that we'd rather be overly-sensitive towards the immaturity of others? Do we all need to remember the sticks and stones rhyme our parents taught us? Aren't we better off by learning how to be unbothered by this stuff?