The main reason for Quake3bsp support over any other is the amount of tools out for it. And artists working with it.

Hey, I am posting here seeing if anyone would be interested in helping with a new game project. My team and I finished Nexuiz, a free 3d deathmatch game a while ago. It was very successful and had a lot of downloads, so we are starting on a new game project (while still updating Nexuiz). The new gam...