I must admit that it's hardly my place to speak of MMOs since I'm not in the range of their tractor beam (or "taget market" how some would say), but I do feel the need to dissect my experience with this type of game. So feel free to comment, rectify and even scold, if you find the need to do so, but remember that this is only an expression of my opinion.
Starting with a bit of my history as an MMO player, I have to mention that I have not started with Ultima Online or Warcraft Orcs and Humans as many of my age did. When those came out I was around the age of ten. No, I started my first quest with RuneScape, one of the most mediocre titles of 2001. Why RuneScape? Three reasons: 1. accessibility, because the game was browser based, running on java; 2. it was free, need I say more? and 3. because it somehow reminded me of Nox, one of my favorite games to date, or it was so probably because I needed something fresh - but still familiar - after a few playthroughs of Nox. But RuneScape showed me what an mmorpg is, with both good and bad. Those factors that drove me away from this type of games are still there, altered or the same, but they still exist. Of course, once in a while I come back, but they still never draw me in.