It's a first, and something new in gaming, groundbreaking so to speak. The first antisocial social game. During beta testing DeeJ made a response to a post on the subject and his answer was along the lines of he would pass it on to the decision makers, from then there has been silence. My belief is the servers just can't handle the demand voice chat on a large scale would generate, and used the "troll ruining the game for others" excuse as an an explantation. Bungie seem to have decided their target audience will be players who are already established teams in other online shooters and decided the casual player isn't as important.