I remember Cata leveling, fly any distance that is longer than your mount. It wasn't fun. Neither was racing to max level in any expansion. We did it because we agreed on it as a team. Now I'm old and casual and take much longer. Flying will be awesome whenever it gets released, as it was in Legion. And there will be a no fly zone like argus in the end game. Annoying terrain is part of the games design, and rewards players who know their way around.