I can tell you ever since the move to Sun Life Stadium fan and student attendance has steadily dropper for a number of factors.
1. And probably the most obvious one, team has been in steady decline since 2003, although it seems things are turning around. Miami is full of fair weather fans, and a small hand full of die hards. Same goes for the Phins, Heat, Marlins etc.... (UM season ticket holder since '98)
2. Move to Sun Life Stadium cut off public transport access to the games. In the old days with the Orange Bowl all you have to do was hop on the Metro down to Culmer and a 5 min bus ride drops you off infront of the stadium. Now, you have to drive 30-45 minutes north (from campus), traffic, parking etc etc... Metro days had to be the best times, get liquored up on campus, drunk as a skunk on the metro, singing the fight songs!
3. Just like alot of other teams, the economy has not been gentle on the fan base. Its obviously cheaper to sit at home in the AC, couch, cheap beer than spend $30 parking, $8 beer etc etc....
In addition, one must remember that UM is only comprised of 10,000 students. FSU/UF/USF has over 30,000+
On the flip side, UF and FSU have stadium on campus and both universities are basically located in cities that only exist because of the university or "college town". So on game day, the only thing to do is go to the game. Unlike say, Miami.
Look at Alabama, Nebraska, Michigan etc....