The point of a skin is that everybody sees it, not only you. Some games allow you to replace the "default" skin on your end so that you see something different. That's not exactly how AH works.
With AH everybody sees the skin you have, and so they have to download it. HTC approves (or rejects) skin submissions, then puts them on the server. They automatically download to players and get put into the skins drop box in the hangar clipboard.
Now, every skin takes up resources. Especially for folks that pre-load textures into memory. If every person had their own outlandish personalized skin and every person were using them, then every player of this game would need something on the order of 5 terabits of RAM just to run the game. A terabit is a thousand GB.
It's just not smart. Not to mention most of these folks are going to take the same base skin and just crudely add guady noseart or add their own name, or bright pink lightning bolts (for the LA7 drivers).
It totally detracts from the environment, the environment can't support it, and at least with HTC approving the skins we have some level of quality control (that is, the skins don't out-and-out suck).
Submitting skins to HTC isn't so much about flying them yourself, it's about providing them for others to fly, in my opinion.
