Maybe they SHOULD care – as "caretakers" of the sport – but the league simply cares about the quality and the profitability of the league.
You can pull all the statistics you want about the viability of prep-to-pro, look at all the anecdotal information, but the pros want to minimize risk when selecting players, and the best way to do that is to delay the age as much as possible. The more information they have – the less exposure. Wherever athletes go after high school – be it NCAA, developmental league, or abroad – the NBA intent is clear: add as many years as possible after age 18 so that the players can get seasoning/experience, and the NBA scouts can gather information.
Corruption in the NCAA? The NBA doesn’t care. And here’s the easiest telltale sign – when was the last time the NBA punished a player for NCAA violations?
As another poster pointed out, when you have an industry generating so much money based on the efforts of players who are penniless, corruption is inevitable. Paying the players isn’t foolproof – you’re simply raising the thresholds.
Good luck, NCAA.
Yes, but at some point, the consumers and advertisers speak out and tell them they need to pay the players. As for the NBA, I think it's in their self-interest also to create a more efficient and effective college system that feeds into the NBA's own player development.