I think it would be great of paintball ascertained the same status as Skateboarding or BMX. They're hardly what I'd term mainstream, yet still manage to attract outside interest and support.
Anymore than that, or push harder to break beyond the realms of "alternative sport", will probably be doomed to failure. It's not as though shooting at people (even with fangible balls) is ingrained in the national psyche.
We could become mainstream, but I think that will only be after a Nuclear War. Where teams from different Subterranean Cities compete against each other in a future sport. Except we'll shoot depleted uranium balls at light speed and fly around on hover scooters. The trophies will be made out of clean drinking water, and we'll get a 100 trillion credits.
Perhaps some people know something I don't.....