IMO, neither the NBA nor college basketball is an ideal environment for the development of younger players (like Daniels). In college basketball, the drawbacks are obvious - practice time is restricted, facilities generally aren't as good, and on top of that, you have to devote a large portion of your time to maintaining a certain GPA that could otherwise be used to expand your game. Additionally, many of the less endearing qualities of the college game - the packed in zones, the over-coaching, the general lack of fluidity - aren't conducive to player development.
But let's also not act like the NBA is some sort of sanctuary of teaching. If you're Andrew Wiggins or Jabari Parker, you can rest assured that whoever franchise your drafted by is going to squeeze everything out of you. It is just too big an investment not to direct every conceivable resource into the development of that player. But what if you're Jeremy Lamb? Posters above have mentioned that he's developed, and that's true. But did he develop at the rate he would have had he stayed here? I don't think so. And that's precisely the problem a lot of young NBA players have - sometimes, the talent of their teammates is so extraordinary (Durant & Westbrook) that they're rendered specialists by the time they step on an NBA floor. I've watched the Thunder a lot the past couple years, and aside from a brief period in which Westbrook was injured, Lamb's basically been designated to the role of spot-up shooter. More problematic, he doesn't play enough to maximize his potential. If he were here, he'd be the focal point of the offense - and would thus enter the NBA with a more diverse skill set - that would have undoubtedly expanded his game under Ollie the same way he would have under Brooks. Andre Drummond is in a similar boat - with another year or two of college, he likely enters the league with a better post game.
Ideally, a legitimate minor league system would be developed (the D-League isn't it, at least right now) where the development of skills would be prioritized above everything else (including winning, which clearly isn't the case in the NBA or college basketball).
Don't get me wrong, the NBA is as entertaining a product as it has ever been. But when guys like Anthony Bennett #1 in the draft, and like clockwork, every year, somebody with strikingly raw skills enters the draft, it conveys one thing: a broken system. Either start paying college kids (which is probably a long way from happening) or adopt a system like that of the MLB or NHL.
How does this relate to Daniels? Well, if the kid is a first rounder, he should go - all else aside, it's guaranteed money that would set him for life if managed properly. But for the sake of his development, I think he'd be better served here next season than bouncing around the D-League.