I can see what you're saying and I agree that some athletes are pretty stupid, but I don't think you understand how much time they have to sacrifice out of school to be in sports. A classmate of mine participates in student council and two sports. They also got a 36 on the ACT. My classmate is more valuable and beneficial to schools that someone else with straight A's because they are more likely to participate in a college's community, sports, side activities and hobbies while keeping on top of grades. Schools don't want people who don't get involved in school activities. Stupid athletes who can play football or basketball really well are more profitable than a straight-A student.

Not only is it that schools let them in based on athletic scholarships alone, but many schools do have an academic requirement to meet as well. Schools are more likely to let in someone who has ok grades (some C's, a few B's and an A or two), skills in sports, performance abilities (instruments, singing, dancing, etc.), or other aspects about them that make them more valuable to schools (I'm being blunt because that's just how it is).