Here is my thing, had JP put in the work to expand his game in college his draftability would not be such a question mark today. His dad told him, you have not prepared like you know you can, that is on the player more than the coach.
Had the chance to play for the team most consider to be the best in college ball pre-season but elects to enter the draft in part because he did not want to risk coming off the bench. Competitors are suppose to want to compete, you are supposed to embrace the challenge and not shy away just because you have a worth challenger trying to take your spot. The NBA is all about guys looking to take someone's spot, if you are not willing to take on all comers for your starting spot & PT in college, you gonna have a problem in the NBA.
He says he felt he had developed as much as he could in the college game, is that what ya call his last season, him perfecting his own developement? Because far to often to me it looked as if he had a ton of things he needed to develope. maybe the ability to hit a jump shot vs college players, maybe the ability to pass the ball to guys in a spot that they can handle it and finish?