Admittedly i don't play mmos very much, but from what I've experienced they are in no way designed around building community.
The focus on instanced, end game raids makes it more or less impossible to have the spontaneous interaction that originally sold the genre. The combat being optimizable the way it is gets rid of any creativity or self expression (and hurts the games in other ways too). Even little things like maps and map markers remove reasons to interact. Then auto matching and market places remove what little community is left between the lines. Community is formed in spite of have design these days.