Probably not. Most football players aren't that smart to begin with[0] and most important intellectual advances are made by a small minority of people.

What's the most significant intellectual contribution of any athlete? I can't think of one without really stretching. It's not like tennis players are making great intellectual contributions and football players are the only athletes who are absent.

If you're talking about the opportunity cost of watching college football instead of doing something more productive, then maybe, but most (virtually all) of the extremely smart people I know do not spend much time watching sports.

[0]: I'm not saying they're dumb, they're just not geniuses

The “intellectual potential of humanity” is such a misnomer. Does it mean not allowing people to do what they would want to do in order to achieve some societal goal? I could say a lot about people who work in advertising for example.