I made this argument to a friend of mine who is a volleyball coach at a local high school. She said that while practice is possible outdoors, a game isn't. There's too much diving to be done on concrete, plus there are added difficulties such as wind and sun which volleyball players simply aren't capable of without additional training. They don't have cleats as part of their equipment to play on grass. It's why beach volleyball is done on sand, because it's easy to safely dive. She also pointed out neither volleyball nor competitive cheer are covered by outdoor insurance so it's just not possible to play those sports (she didn't know about basketball). She tried to get a few beach volleyball games going but was told the insurance wouldn't cover the sport outdoors.