MMOs are an expensive and risky business.
I think that's the main point. And it's true not only for MMOs but game development in general. You just have to look at how huge nowadays AAA budgets are to understand (from an economic point of view) that you can't risk breaking too much new ground, which allways bears the danger of failing. Still from the view of a non-casual/passionate gamer it is a shame that more and more you have to lay your hopes on small independent developers to truely see some "evolution" or "innovation".
As far as MMOs go I just received word about an ambitious project called "Embers of Caerus" which is only in prototyping stage and far from being a finished product, but the visions of the guys working on it have the potential to really change some things in the genre if they become a reality. Especially by proving that some claims often made about things being impossible in MMOs due to some technical restrictions simply are untrue.
But enough of hijacking this dicussion. Like I said it's a missed opportunity in my view to rely on predefined factions and seperated territories for them, but that's hardly a game breaker for me. Such a world still can be huge fun to play in. And if it's done well you only "notice" it because you know about there being parts of the gameworld not accessible for this character. As I'm mostly interested in the PvP part and some nice RP and less in exploration and seeing everything it's still the opposite for me: I was disappointed about the first announcement made, but the more details get revealed the bigger grows my interest in this game.