Then you haven't been comprehending, or fully reading, what people are saying. Most of the complaints I'm reading are from people who have done countless world quests. They've exhausted all the open world content months ago, and are pointing out that there's literally no reason why they shouldn't be able to fly at this point. Most of the suggestions are that flight should be obtainable in the launch content after being done exactly once, in order to see the game "how blizzard intended it"; NOT after a year into the expansion at some arbitrary time frame.
You also failed to recognize the context of previous expansions. This isn't a new game that they're building in a vacumm that players have never encountered before. This is a well-established game with a high level of player expectations. Sure, Blizzard might want to create a 100% grounded game, but it's clear that they CAN'T do so and deliver a product which will sell as well. Otherwise why return flying at all, at ANY point?
This adherence to trying to force the issue is going to cause more harm to the game than simply acknowledging that flight is something that players want. IF they try to pull a bait and switch and give flight back, followed immediately by a no-flying island as open world content, it's going to backfire on them.