Chatting in ALL has it's advantages and disadvantages. For the most part it's easy to get around. But in a game where someone is losing it is inevitable someone is going to talk trash, and beyond trash. Insults to someone's intelligence, skill, or handicap is uglier than sin (pardon the pun).
Having the ability to mute someone in the game would be nice. When someone is typing insults and worse; I had to leave a game it was so bad. Sure I was going to lose but I wanted to stay all the way.