I had an active account on WoW for 3 years, played whole WotLK and some of Cata but ended it in November.
And not to go on a rant here on anything
But I don't think games like Diablo, LoL and SC2 fits into the MMO genre, maybe DoD:s if the player limit is high.
Tainted, MMO:s are games which many players play and interact with eachother on the same server, Diablo has a player limit of max 4 people playing together, LoL/HoN, max 10 players, Starcraft, I don't know exactly but it isn't "Massive".
If we would follow that logic, every online game would be an MMO.