The reason that UNC Charlotte grads (many, not all) do not supports the University is the same reason that many of the students don't - school pride, and no sense of connection. Athletics are what most universities in this nation are known for. I personally don't know what degrees Notre Dame, Syracuse, Cincinnati, etc, etc, specialize in, but I do know what sports they excel in. That's what gives people pride and encourages them to give back to their school.
Sure, we can wait another 200 years to get a larger endowment and raise 1000 dollars a year until we have a football team in the year 2250, but there is no reason why UNC Charlotte alumni need to wait and play it safe. Every other football school in this state could surely use more money for education, but they are not shutting down their athletics programs to improve their degrees.
As alumni build pride and establish a connection to the University, guess what...they are likely to give back to the University in general. At least then they would actually go back to the university after graduation and realize what is going on on campus.
How many college football fans do you think there are on the UNCC campus? I'll throw out a random number - 8,000. When football season comes around, these 8,000 people pick another team, buy their merchandise, watch them on TV. It really does break the tie to your school when you are pulling for a completely different school for several months out of the year.
Starting a college football program is of course expensive, but Charlotte is a wealthy city and the area has over 75,000 UNC Charlotte alumni, in addition to the 22,000 current students. Add in the million-plus people in the area, and there's no reason why a football program shouldn't be a success.