Ok, so the problem isn't a state of the size of Alabama having 5 FBS programs? The problem isn't the massive popularity of Alabama, Auburn, and the rest of the SEC in the state? The problem has nothing to do with the fact that UAB football can't even muster enough fans to hold a real rally? The fact is they can't get their fans to show up anywhere.
Last time I checked, neither Troy, nor South Alabama, not to mention the dreadful UAB, were selling out stadiums left and right. There simply is no real demand, period, end of story. When you can take those three programs, combine their attendance and still fall far short of Auburn's attendance, you know what's going on. Michigan has the same problem to (too many FBS programs no one cares about), they have a program that has the city buying up tickets to keep it eligible, like Birmingham does with UAB. Oh wait, I'm sure it's their stadium to that's the problem right? Not that everyone is fan of another team?
Why on earth would any SEC fan miss out on SEC games, or even worse an Alabama game a short drive away to see UAB play? The simple answer is they won't, and they don't, and they wouldn't even if UAB was playing on a field made of gold. Birmingham regularly comes in as the best TV market for college football, and they're not tuning into UAB games, they're watching real teams play.
Alabama always had good attendance at Legion Field, UAB never did. The idea that the problems are the field is just so... ignorant of reality. They couldn't get anyone to go to their games, period, they can't give away tickets, but the problem is where they play, yeah... they need to spend 50 million so they can have a nice fancy, empty stadium. Is Legion Field a crappy place to play now? Sure is, and it's better than UAB football deserves. The UAB program was started under the delusion that they could get Alabama fans in the area to cheer for another team instead, but clearly that isn't happening.
Let's try to puzzle our way through it. How many fans do you think UAB would get hosting a conference game at Bryant-Denny? How many fans would Alabama bring in if they did a conference game at Legion Field? We all know the answer... it's not the stadium.