pcliu i agree that rude people in the game bring nothing good, but no human being working in support can be wise enough to make right judgements and differentiate people being rude for now reason with those joking. banter can take different forms and unless you know a person very well, you wont be able to tell if he wants to hurt someone or just being friendly. for this reason i think it's better to keep all those low quality people trying to ruin our mood, just so that other people can joke between themselves freely
i also think that the better solution is not ban, but restrict the communications to team only. regardless of what kind of people they are, it's still a game they payed money for