Don't forget, the NBA puts you on a rookie contract. So you can't make the BIG money until you get through those years. So there is still incentive to get to the NBA as quickly as you can.
It actually doesn't do what you claim at all. I haven't seen (doesn't mean it doesn't exist) any rule that says if you sign with Dinkytown Athletes you can't go make your own deal with 3M. Maybe DTA does have that, so freaking what. Then go at it on your own. Be a grown-up, make your own...
Sure its happened. But the team is no longer required to take you back once you put your name in. So it lets the team off the hook if they'd rather you move on.