Everything is too easy, instant gratification...there's no challenge anymore - it's possible I've just been playing too long.
The only fun part of an expansion anymore is the first few months when leveling and gearing up is fresh. During WoD once you did that there was nothing else to do but raid. We'll see what Legion has to offer - professions will probably still be worthless, world quests will dry up in meaningful rewards, dungeons will be all but obsolete...same thing that happens every expansion. God forbid you have an amazing trinket be a low % drop chance in a mythic dungeon or something...Ya know..like an RPG.