For me, it could be that USF up until pretty recently was thought of as a commuter school. When Betty Castor became Pres, she started making campus look a bit less like a prison from the 1950s, and with that we eventually got new dorms, a Greek row, parking garage, and some pretty major beautification to the grounds. To me, USF has changed a huge amount, and shook the commuter label, but maybe that old perception is still there? That we're not a "real" school with culture and traditions and campus life, etc. And so there's just not that emotional connection with the community, alums, etc.
Or maybe the Tampa area is just not interested in a local university no matter what we do and students run away screaming once they get their degrees, never to look back again?
It's a really interesting and weird problem to me. I have no answer.