Think about how many students on academic scholarship function as RA's in their dorms. The athletes can't do that or perform a function a couple of hours per week manning the front desk in the library (or some other similarly easy job where they could not only study but earn spending money).
Think about how many students on academic scholarships have multiple scholarships that actually pay them more than the cost of tuition, books, etc and they end up having some left over for spending money. The athletes have to return those, as the author of that article explains.
There are a lot of stupid rules that were put into place when schools like Oklahahoma were found to be paying their players to cut the grass...when their field was artificial turf. In the NCAA's infinite wisdom, instead of coming down with the hammer on every school they found breaking the rules, they decided to enact Draconian policies that hurt future players...all because they're never going to really step hard on the ones they find cheating if that school is a major source of income for the NCAA.