So mob tagging and sharing quest mobs is only bad in WoW?
Putting words in your mouth.. you argue that sharing mobs for quests is frustrating. Now I haven't played GW2, but unless everything is somehow shared (no xp penalty?) then sure. If that's the case GW2 has an environment that can't impede your questing due to other players...
So the only issue is that CRZ, by making zones more alive, may slow down your leveling. So far I can't see anything that says anything other than you want to play singleplayer, where there's no competition in the world. No conflict.
How boring