I feel like that would've been a pretty terrible decision, though. Delaying Cataclysm until January, that is. Tell me, which would you rather have, then: farming Heroic Lich King for 8 months (since if you really are in a 13/13 guild, I'm assuming you killed Heroic Lich King very early) and getting you and every one of your alts an Invincible, or farming Sinestra for 2-3 months, which is going to be the approximate amount of time we have until Firelands?
I really hate to say it, because I don't like posts that basically say 'if you don't like it, quit!' because there is nothing wrong with negative criticism, but really, if the game has truly become a job and you hate farming things to the point that after just a few weeks of farming, you are already bored sick, perhaps you've simply outgrown WoW and it's no longer the game for you. There's more punishing games out there, if you're into that kind of masochism. I hear a Demon Souls sequel is being developed.