Truthfully, burn out happens in all games. No matter the genre or game, at some point we all take a step back and say: Enough. It's not that the game is bad or the player is angry, it's just time. I don't blame you for feeling this way and will wish you Godspeed and phat loots.
The greatest thing about MMO's is they are always here when/if you come back. Having played dozens of MMO's in my time, I get burned out on one particular game and switch to another for a while, maybe even switch off to yet another. When I feel the need for the game, I can go back to it, no harm, no foul.
Good luck!