BoK has been discussing the PvP epics vs. regular epics discussion, and I thought I'd weigh in on it too...
Timesink. This game and virtually all other MMRPGs are unfortunately purely designed in this way, to waste as much time as possible to get as minimal a reward as possible. Part of the problem is the complete avoidance of the concept of character death - if you cannot lose your character in any way, shape or form, the rewards have to be slow and time-consuming, so that you cannot perfect yourself.
But they're really too slow.
People complain about being able to get PvP epics, but it isn't as though they're handed to you. I have 3 pieces from months of play from the arena, and the other 3 I earned from what can be asbolutely mind-numbing BG PUGs. I don't think there was any lack of effort on my part.
The difference is the staggering amount of time you comparatively have to spend in PvE efforts. Rep rewards, raiding time, all of these require ridiculous amounts of time put in. The only way to get everything out of the game is to sacrifice all of your other games and many other interests. At 10-15 hours a week I can never catch up to any of my goals, especially not with raiding in the schedule, and getting an epic flying mount is almost certainly never going to happen at this point.
Long story short, rewards take far too much time as it is. PvP rewards may be a bit too easy, but I believe the effort required to get PvE rewards is so severe that it makes PvP look a lot easier than it really is.