Fair enough and my own personal reasons for not buying WoD (yet) is I'm waiting to see if it's just MoP 2.0 for endgame raid or die.
Flying mounts are really a non-issue for me. They annoy me but I'm not going to quit over them. At the same time, I wouldn't throw some rage fit if Blizzard had said we can fly the moment we enter WoD.
Do I think the game would be better if flying mounts were never implemented? Yes.
Do I think it's possible to return the game to a non-flying mount state? No.
Do I think that flying mounts need nerfed? Yes. Ground mounts should remain a viable choice and not just arbitrarily because a dungeon or raid zone forbids flying mounts.
All that said - I really think we should be able to mount up anywhere we want - outdoors/indoors/caves/dungeons/raids. The content should be designed to prevent certain types of mounts from being effective though. I'm not fond of turning things off to just turn things off - I like there to be a story reason to support such a decision.
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There are exceptions to every rule Superman and I left some room in there for exceptions.
There are people that have posted in this very long thread that somehow removing flying is the killer nail in the coffin though and to me, that screams "Scapegoat" issue. They are looking for a reason to leave and "no flying" is exactly the nail they need to break their addiction in their mind.