Wait... I thought that college was for getting an education. Why are they spending so much time on athletics or body building if they're there to learn?
However, your point is taken. It would probably be better to use either BMI or Body Fat Percentage, depending on the circumstance.
I'm sure there are even very academically minded people that like taking care of their health.
In any case body fat percentage has some flaws also. The biggest being it's not easy to get an accurate reading of what's somebody's true body fat percentage is. Those electronic scales don't really do a good job. To get a good reading takes being put under a water dunk test or I think there are even some sophisticated infrared techniques that are used, but those aren't cheap and they are time intensive. Really the best cheap method is just looking in the mirror or at somebody else, but that is too highly subjective for something like this. Knowing about the people that are really fat and overweight wouldn’t be that hard, but the borderline people would be very problematic. You could measure with calipers, but that's hard to stay consistent from person to person or even from measurer to measurer, and then again I would hate to fail because I was just barely over when I got the person always measured high.
Really, besides the silliness of using somebody's physical fitness to decide if they should pass things that are academic in nature it's just way more trouble than it's worth to even do that fairly and accurately.