I wouldn't expect most players to do all the quests on 8 characters either. I sure as hell won't. But like those who did the Insane achievement or try and find every mount in the game you'll also have people that want every appearance unlocked. More power to them if they want to spend their time on it. I'll be doing laps in Org.
EDIT: Transmog rules are the same as the Wardrobe because the Wardrobe is an extension of the Transmog system. They are not separate systems.