I went to Purdue. At Purdue, athletics and student housing/dining are entirely separate divisions from the academic side of the university. Each of those divisions is required to be self supporting without needing aid from tuition dollars.
That being said, a mandatory part of tuition is funding for the student gym. I think it came out to be something like $100/student/semester which I'd consider reasonable.
Any individual cost looks justifiable. But they add up. And ultimately, students pay for many of them. With a gym, especially, you can make it optional and charge students who want it. That's the model in many other countries. Similarly, the school newspaper, political clubs, other student activities all get funded from somewhere.
That being said, a mandatory part of tuition is funding for the student gym. I think it came out to be something like $100/student/semester which I'd consider reasonable.