I enjoy the scenery when I'm in the mood to enjoy it. I'll hop on my flying mount and sit in a tree and look down and take screenshots of the beautiful art that the Blizzard artists have poured their heart into. I respect their work, as an artist myself. I don't mind that in every new expansion you're grounded until level cap; it kind of got annoying on my squishy mage but invisibility's a great cooldown.
That said, if they "did something as trivial as giving people gold for every flying mount they had or converting some to land versions" I'd be pissed off. I'm also a mount collector - 195 of them on my main - and a majority are flying mounts, and those flying mounts took a hell of a lot of time and effort for me to collect. Rep grinding, soloing dungeons, hating tanks who are like "lolol look at what you farmed for a year and I just got it out of a bag"... it's all part of it. And if you think that Blizzard would just snap their fingers and take that all away from me, and the many, many other people who collect mounts, and that we wouldn't be INCREDIBLY angry, you're wrong.
And look at all the development time gone into flying - not just the mounts themselves, who have different visual and audio effects when moving left, right, up, down, idling in the air, moving forward from being idle in the air, idling on the ground, and mount specials - they design the scenery to be seen from above. If they really put all their heart and soul into ground scenery and none into aerial, then buildings wouldn't have roofs. But they do. Because you can make something visually appealing from all angles, and if you do, then you're a damn good artist.
And I can say this without a doubt, because I love flying for the sake of flying. Many a time I'll hop on my druid and go into bird form and spend hours just flying all over the old world, looping through trees and around buildings, and just perching on places and looking around me. It's fun to fly. It's fun to use flying to see the world, just as fun as it is to use ground mounts to do the same.
There's nothing stopping you from enjoying the game on flying mounts. Don't be silly. And the best part is, when you don't want to stop and smell the roses, you can just go fast to your destination. I know I'd hate archaeology if I couldn't fly. Some of those places are just WAY out of the way. Townlong Steppes has like five flight points and they're all centered in the same spot - can you imagine going to fight the Pandaren Spirit Tamer there? Or doing Niuzao's dailies? It would take an hour to get there from the Vale. It'd be unbearable.