Of course it would (WILL) ruin college athletics. But the fact remains that marketable college athletes are treated differently, contractually, then in just about any other money making enterprise that you can think of.
The model is about as far from capitalist as it gets. Everybody gets the same compensation (scholarship to the school) regardless of whether you're a star quarterback, whose skills would be worth a $50 million contract in a professional market, or a backup for the woman's softball team. Add in the fact that administrators and coaches split up the revenue for themselves, and actually you've got a model pretty comparable to communism.
In the market, any contract is reviewed for basic fairness. Contracts that a party has no choice but to sign are called contracts of adhesion, and they are routinely rescinded by courts.
Non-competes are reviewed in court for overbreadth in all areas, geography, duration, scope of restriction on the type of work, etc... If Fields challenged his scholarship agreement under a non-compete standard, I can promise you it would get blown up in Court.
The NCAA doesn't want to have this argument, because it is a loser. So they are allowing the transfers, and granting more and more of these ridiculous waivers, as kind of a pressure release valve to avoid the whole system blowing up, which it will, inevitably. The skills these kids have are worth too much money, and they're figuring it out.
It has to come to an end. The unfairness is too blatant. And it will suck. But when it blows up, and these kids are grabbing cash just like everyone else, then THAT will be consistent with capitalism.