MMO's can be entirely "successful" (ie. make money and have a loyal fanbase) without needing to beat WoW (or emulate it).
Take Eve Online. The ultimate in niche titles, a space game with a learning curve described as:
And yet CCP games are making plenty of money, they have a loyal fanbase, significant concurrency in a persistent online game etc.
The secret is that they aren't trying to beat anyone, they are just making a game to appeal to a specific market. It's a sandbox and the human drama is an important part of it, much like Star Wars Galaxies. (I still boggle at that scam run by a merc corp years ago to essentially destroy one of the biggest powers in the game at the time...).
The possibly good news is that with crowdfunding/kickstarts starting to turn up some pretty big cash, game companies may actually realise that there are enormous markets available who don't just want retread pieces of crap, who will support titles that take a risk or appeal to a more specific audience.