Blizzard say whatever is flavour of the month to please the forum populations,
Not sure what a ton is to you but it aint anywhere near the 10+ million subs that were all happy with flying in 2 continents, (1 being a planet i guess).
This whole flying arguement is nothing more than a coat tail that vanilla purists have hung on to for dear life. It was something they could use to argue for vanilla servers.
Many things bug people about the game, flying, dallies, unending grinds, welfare gear, etc etc.
Of all the things, flying is way down the list, you ask retail players what does more damage, flying existing or all the stupid gating systems, catch up systems, endless grinds for power etc.
Futhermore in terms of TBC and Wrath, flying is only in Outland/Northrend so any wpvp in STV or Southshore (which I promise will still be hotspots even in these expansions) will still happen without flying.
This is something I think should have been the case, Cata should NOT have opened flying in vanilla zones, they were designed without it, BUT this would be odd if MoP, WoD, Legion and BfA all had flying and vanilla didnt so it had to be done.
The current iteration of flying is to lock it behind achievements - NOT restrict it! This is because using a gold based currency in retail would be way out whack, how much would it cost after all these expansions, new players would have no chance. Getting flying is easy, all you have to do is play the game and wait for pathfinder part II to be released. You’ll have all the rep and stories done by then.
If anything its easier to get flying now than ever, no need to grind out x amount of gold to buy flying per expansion.
So no flying didnt ruin anything, it changed a few things but not ruined.