Ah yes, faster flying on a 5 minute cooldown such an unfair advantage.
But druids having an instant interactible flying, ground and underwater mount, mages porting across continents via a single spell cast, Death Knights and Palas getting another 20% bonus mount speed in all situations, Shamans having 2 seperate hearthstones is a-ok.
One likes the number on the right to match the number on the left, the other just likes to see bigger numbers.
More than half the mounts in the game are already invalidated, as flying mounts are functionally superior to every ground mount.
That isn't stopping them from making more grounds mounts, let alone anyone from using them.
Besides, they are not gonna remove hover flight completely anyway.
For one they'd can't just turn off flying on non-dragonriding mounts, and it would serve as an accessibility option.