Athletics are good in the sense that activity is good, but they also carry with them all kinds of undesirable activity and focus. Americans seem to be way too focused on athletics to the exclusion of other things. If some institutions did not offer athletics, those institutions could focus their resources on other things, and that might prove to be beneficial in new ways.
Athletics in colleges helps a lot of students who could not afford college in the first place. It also motivates athletes to keep their grades up. If an athlete does not make it to a professional league he or she can use the degree he obtain in college to get a good career.
Yes, because college is about more than just classes. Building community is also an important aspect of the college experience. Sporting events are an excellent way to foster a strong campus community. They are also a fun way to bring alumni back to campus, which raises money to be invested back in the college.
Additionally, sports often provide scholarships to students who may not otherwise have access to funding to attend school. College athletics opens opportunities for many people.
College athletics are a great way to foster school spirit and to bring in money from the community; however, I do think that the overall focus of a university should be on academics and not athletics. A person should go to college to get an education and earn a degree, not with the central purpose of playing football.