It's just a matter of taste. When it comes down to it, space is just another setting like jungle, city, desert, snowy wastes, and so on. I'm currently semi-addicted to Project Reality, and I quit the server whenever it gets to a city map. Not because there's anything wrong with them, but because street fighting is too chaotic, hectic and fast-paced for me, and I prefer the open expanses of desert where I can see what's going on. Jungles and forests come in second popularity-wise, as long as they're not maps where the whole place is covered by dense woods. Then I lose overview (and interest) very fast. I'm still hoping I'll enjoy Endor.
"One of the bitches actually gave birth while she was attacking, and her puppies joined in on the carnage."
--the awesomeness that is Boatmurdered.