I feel like they have someone on the Dev team thats spouting off "The Vision" when it comes to making everything account wide. Or maybe its because getting rid of those grinds would cut down on the amount of time players play the game. Though, I think I would play more if I didnt have these major time sinks that I know I have to slog through just to play another character... I was thinking the Legendary Cloak Quest wasnt able to be skipped on Alts because it encouraged veteran players to go back through ToT. In essence, giving new/returning players a quick queue time instead of a Dead Zone.
Though, definitely having things like Flying being account wide would be more appreciated than anything. I cant really think of a reason the Dev team is keeping things like that down to a single character. The gold costs arent a huge time sink and the cost of them doesnt take a reasonable amount of gold out of the economy. The mounts were doing that plenty well.