Closest thing I've played to an MMO is some pure-text thing where you got to pick three fights per day against other users, but everything was automated. It was run through some GameFAQs board (possibly Board 8?) The goal was to end up the highest-level character at the end of the 2-3 week period (my character titled "Weakling Mage" was either first or second I think? Someone got higher than me, but there was some question of whether he'd fought an extra battle on the final day).
Though, personally MMOs aren't really my style for a few reasons:
1. I'm not a fan of enforced grinding. Granted, it's not like I never grind for fun--I've done it in...three or so games when I wanted to see the game from a different angle, but it's not -usually- my idea of fun.
2. In a PvP setting, I don't like the idea of handicapping inexperienced players; if anything it should be the other way around. I'll make an exception for that silly user tournament I mentioned above, where fights were entirely automated so the actual strategy became "do I fight someone higher level for a bigger exp bonus, or someone lower level for a guaranteed exp boost". However when I actually enjoy the fights themselves, I'd prefer to have a level playing field.
3. I'm afraid of the timesink. Not an issue with every MMO, granted, but I look at some of my coworkers who play 40 hours of WoW a week, and just have stopped playing all other games (to the point that they'll get a new system at launch, and then not even take it out of the box for months).
4. Some MMOs aren't exactly known for their maturity level; it's the internet--homophobia happens. Granted, I post on message boards, but I've already spent time finding intelligent message boards >_>.
Nothing wrong with the genre, really, just...not my cup of tea at this time. (Who knows? My taste in genres seems to shift every three years or so).