The game is much, much different than it used to be. There is an enormous premium put on shooting and defending. Two things Dejonte is terrible at this moment.
I wouldn't say Dejounte is terrible at D. He has some awesome tools and he moved his feet well in the game I watched. His length helps him get in the passing lanes and he deflects a ton of balls, similarly to Dante his length also helps him recover in situations where he's beat... That's not to say he doesn't have work to do on D - sometimes he gets beat because he seems distracted/misreads situations, but I think he has all the tools.
The main issue I have with him is that he seems to get tunnel vision on offense and gets out of control. I am not sure he will ever be able to run a team as a primary ball-handler.