I think one of the least fun things about leveling is knowing the gear you're geting has such a short life expectancy. Level 70-78 gear just doesn't have any appeal and I could usually care less if there is an item reward or pure gold when completing a quest. I agree that an expansion just seems like a time sink for everyone to spend 50+ hours (I wish I could level from 70-80 in that short of time) until the real game begins. Of course, the more work you put into anything the more attachment you feel and the more satisfaction you get seeing them succeed.