I once attended Bum, Jr.'s first D1 with his mom (a Pac-10 school) "Fall World Series". It was promoted on the internet. I found it akward as no other parents, students -- no one! -- showed up. After he transferred to a Big-12 school, there were hundreds at the fall games.
It has a lot to do with the school, the culture, and the weather. But who cares. I'm proud to say I showed and no one else did.