Here is Miami's advantage...they play in the most talent rich area in the country for high school players.
Miami is a mere competent coach away from always being in the National Championship picture at any time. They were already on a pretty significant probation in the mid-90's and within 5 years they won a National Title and were back on the scene in THREE! Why? They had the best damn evaluator of talent in college football (especially defensive) as their coach.
When Miami started getting really national with their recruiting is when things went down hill. We basically were recruiting guys with their hands out, and if history tells us nothing, when you recruit nationally, especially the players with their hands out you are going to get busted (SMU as example A).
Miami doesn't need to recruit nationally. Maybe grab a QB from California, Pennsylvania, or Texas...maybe grab a few offensive linemen from the mid-west or northeast, but in general, we really never have to move out of the area for talent...this is never more true when you have a coach that can assemble a good staff.
Miami is the perfect stepping stone job for a coach that wants to do big things not just in college football but the NFL level.
But, you are right...facilities are nothing to write home about, the college is a small one located in Coral Gables, small booster base, etc. But, for some reason...it works. Just need a guy that can coach and buy in to the program (Howard, Jimmy, Dennis, and Butch all did while Coker made it a country club and was bad and Shannon was just a bad head coach).