I have no interest in discussing the matter, so I can't really blame anyone. I've seen exactly one person come into a conversation and have the opinion that not flying is the best thing and it should stay that way (a week or two ago). Two people started talking around me, seeming to try and persuade each other of their points of view. I told them I didn't care why they thought not-flying was great, it's not great to me.
Perhaps on the far end of the RAWR spectrum is Ember. I think she makes very good points. Beware there will be F-bombs ahoy, she is well and truly angry. The points still stand though, and I don't think she's wrong to be angry about being told flying won't come back.
I'm more blah about the whole thing. I want to be able to fly. I enjoy it, I like being able to zip around look at things, look for things. I get lost on the ground, and I usually play short races so it's hard to see over rocks and such. Being able to fly up gives me perspective that I don't have otherwise. I did pet collecting and archaeology while I was leveling, as I passed through the areas. I don't do it at all now. Which is a shame. I actually kind of like archaeology, but I'm not going to spend ages wading back and through mobs to do it.
I'm not mad though. I thought that leveling without it was fine. There are plenty of ways to skip mobs and content without it, even before you get the robot in Gorgrond or Aviana's Feather. I figured out the bare minimum to open up level 2 garrisons, to speed my alt ways.
Honestly the only thing not flying means to me is that I play a little less. I don't know if I'd be more likely to level an alt if I could fly or not. I've done a few, most of them faired fine without flying. Mostly they leveled passively through XP missions and mining in the garrison, then brief bursts of questing.
I'm pretty sure I'd play my main more if I could fly. I'd be looking for treasures. I'd be looking for rare spawns. I'd be doing pet battle trainers and fishing up lunkers. Instead when it's not raid night I log in, do some treasure missions, open some salvage, hit the AH, and log out. Lately I've been working on the legendary quest on my paladin and I've been trying to spend a night a week on that.
Still I'm not mad. I'm just not playing as much, and I'm a little bummed.
To cheer us all up, let's look at this flying chocobo. Because yes, FFXIV is adding in flying now.
Video captured from the Twitch broadcast on May 21, 2015 Letter from the Producer LIVE Part XXI. The flying bits start around the 40 minute mark.