I don’t think the “plus more” is correct. For one thing, some students contribute athletically without athletic scholarships. Luke Maye was a walk-on, CJ Lee and Dave Merritt were walk-ons, yet they contributed athletically. Brian Griese was a walk-on.
And unless an athlete is truly exceptional and make the NBA or NFL, which most even at a place like Michigan are not, they are likely to succeed out of sports exactly because of the education and alumni connections, etc.
Also, why is contributing athletically “more”? Athletes can become successful, provide exposure, donate money, etc., and so can students admitted on academic scholarship. Different students are more likely to do so in different ways. If Stephen Ross donates a hundred million dollars, is Jalen Rose really doing more? Maybe Lawrence Kasdan gets a scholarship because he’s good at math, but then writes the Big Chill and gets exposure for Michigan in the movies. There are various ways to contribute, and it’s not clear to me why doing so via athletics is somehow qualitatively different.
Perhaps you think athletics are more of a “sure thing.” For one, this may not be so. Athletic scholarships may represent more of a risk. A student with a high SAT score gives benefit simply through that score. An athlete who doesn’t start on the football team may simply “take up a scholarship.” But in any event, even if you think athletes aren’t getting a good deal or return, that doesn’t mean the scholarship is irrelevant to what they’re receiving.