I think it's fun because it's easy to get into, so beginners can enjoy it, and gets progressively tougher, allowing for a good balance of competition.
to play, you don't have to run a lot, so beginners can go a full game without passing out, but of course conditioning requires running to get better
I think the movements of volleyball are innately fun too , the swinging the arms underhand together to hit the ball is pretty rudimentary, and giving the ball a good thwack on an overhand swing is very satisfying.
and then teamwork team building self esteem girls in tight shorts blah blah blah etc.
