I don't think Blizzard understands how to make a social game, and I'm beginning to realize they never did. The game used to be more social, but it seems like that was by accident instead of by design.
Like, you used to have to use the chat channels to find a group for a dungeon run. That forced you to chat. When they added dungeon finder, you didn't need to chat anymore, making it less social. When they made cross-realm things happen, zones felt less lonely which was good for being social, but then it meant that you no longer ran into all the same names over and over, so you stopped knowing people. That was really bad for social things because it meant that people who behaved badly didn't get a bad reputation and people who behaved well didn't get a good reputation.
This is a great feature given the current state of the game. But, I wonder if it will have the unintended side effect of making the community even more toxic.