So each of those guys would have magically not been a bust if they returned to college? I've got news for you: most of them just suck.
They all got a ton of chances. If the best coaches/training/etc in the world couldn't save them why would a college coach? It's such a bizarre stance that many people have that college coaches are better at development than pros. It's not 1993. The Thunder have an 8-man development staff. They're not game coaches, they don't sit on the bench. They exist solely to develop their young players. 24/7, without school getting in the way.
I also don't understand how playing another season of college basketball--which is hideous and sloppy and slow, the polar opposite of the NBA game--is going to help these guys.
Having Bouknight face triple teams and a packed paint and playing at a glacial pace will, if anything, harm his development.
He can play 18 mpg and learn the NBA game and live in the weight room improving his body as a rookie, all while making $2m. I'm sorry, on no planet does UConn offer him a better developmental option, even financial reasons aside.