Why do players have to make the maps?
Why make it so hard to make maps?
Why not hire someone to make new maps? 
My best guess.
(1) Players want to (it's fun) and since it's a variety of creative players, the maps vary.
(2) I've used the terrain editor and made a small map. Was easy and quick. Took less than a day in total to learn the TE, make the map, and fly on it.
(3) see 1 and 2 above, and saves money. Although I do wish they had someone to update/improve them full time, but I already put that on the wish lst.
