There is no room for adventure.
I remember getting lost in Dark Age of Camelot and found a town in the middle of nowhere. Granted, it was a new "hard to get to" area of the world but it was still fun and unexpected. Also, it was quite a "dark" game, as in, when it was night, it's pitchblack. You had to have some kind of lightsource to see where you're going.
MMO's these days are just "themepark after themepark". World of Warcraft is just one of the offenders. When the game was new, going to Ashenvale or even the Barrens was exciting, but it was pretty "meh" after a while, as it was quickly accessible. However pretty Ashenvale, or Duskwood might be, it's not really fun anymore, nor are any other zone either.
Turbine did a good job on this however with Lord of the Rings Online. To complete everything, or see every sight, takes time but, you don't really have to. And to get to a certain location, it takes quite some time and you feel rewarded when you do. In WoW, this was almost a punishment somehow. That, or players (even me) have become lazy?
Perhaps this is why I enjoy The Elder Scrolls, Elite and most rpgs more than MMO's. I couldn't give a fuck about some high-ranking arena rogue wants and needs, or for some asshole who thinks gearscore is a good measure of 'skill', that's not why I play a fantasy game... but I still want to play with others. I somehow feel that "my" game haven't been made yet.