If you amortized their donations for new facilities, upgrades, equipment, etc., it would add $10 million to $20 million a year in operating expenses. Most schools aren't making $10 to $20 million in profit from football and basketball. There may be a few outliers like basketball at Duke, football at Alabama/Clemson.
I just think that the $400k to $800k of benefits that these students get for 4 years (tax free, I might add) are worth a lot. If you look at a 50-week annual work schedule, the players are really just working part-time. Maybe they average 20 hours a week on an annual basis.
Most of the football and basketball players would never get admitted to the universities where they play. College sports have been a great way to increase diversity on campuses across the country and have served this aim very well. The athletes are overplaying their hand.