The rationale went like this: "You can't coach him,'' one coach explained. "He'd always have something over you, so how do you make him practice hard? How do you make him go to class?''
this coach nailed it. the people that think players are all being paid are, in their own way, as naive as those who think their school is driven snow.
That's a fundamental dilemma that's been around since the very first player got paid. Number one rule for cheating; plausible deniability, e.i. assure it's near impossible the paper trail could lead back to you.
Funnel the benefits through intermediaries. Boosters, friends of the programs, agents, business owners, and often persons with seemingly no, or very little, connection to the school at all. Any communication is done by an assistant, likely a ways down the chain of command.
If a player spills the beans, everyone claims to know nothing. Worst case, the heat comes down and the NCAA wants blood, the assistant becomes the "rouge" offender, acting on his own without any knowledge by the coach and the higher ups.
Benefits can be provided in a way that looks legitimate, and/or is less likely to be noticed. Jobs for coaches and family members, house for mom, "job" for the athlete at a local car dealership, etc. Also, a player isn't likely to talk if it means his mother loses the mortgage on her house and her new job.
I more or less agree with your basic point. The crazy high percentages of athletes that some people claim are receiving major benefits (beyond common stuff like tutoring) would seem unlikely, due to the complexity, planning, and risk involved, among many other factors.