You haven't gone back to other zones, but you might in the future, because there's a lot of content that forces you to go back. Societal quests, treasure maps, and FATEs alone will cause you to get very familiar with almost every region.

However, it's true that this setup doesn't accommodate players who do MSQ -> Raids/Trials -> PvP, not necessarily in that order, and aren't interested in the rest of the game's content.

That's totally valid and in that case, I can see how not unlocking flying right away would be annoying. Unfortunately this is one of those scenarios where the game is meant to accommodate the person who wants to take their time with the story and immerse themselves more easily. I find that when flying is available right away, I'm going to use it even though I like to take things slow, simply because my brain is dying to know what happens next in the MSQ.

Being forced to travel on land only forces you to slow down, and this is preferable for a lot if not most players. So, I'm sorry, but I wouldn't expect it to change any time soon if at all.

You shouldn't have a hard time finding someone who will fly you around to all the aether currents, though. This way you'll get done in no time.