WoW is the perfect example that shows that the "community" and "communication" in MMOs happens because players have to do it, not because they want to do it. In early WoW it was pretty much the only way to progress through the game. Without communication you couldn't do anything, so people communicated. In retail WoW you still have that to some extent in higher difficulty endgame content. For everything else you don't have to talk to anyone ever. You could hide your chat window and still get to max level, see all dungeons and the raid.
And the times of people just wandering around and talking to each other are long gone. For the vast majority of players MMOs aren't a novelty anymore.