Tell me that you saw JB's fadeaway jumper on the baseline last night and that he still cannot shoot. The eye test tells me that he's talented, very athletic, runs the floor, drives to the basket, and plays defense. He will need to show consistency and at 19, it's expected that he will go through shooting droughts. The potential is there though, and he's already hit a couple of tightly contested difficult shots.
If his shooting never takes off to where we want it, I don't see why he can't be a Jimmy Butler/Andre Iguodola type player for the Celtics. A super glue guy that could be the 3rd best player on a championship team. He can change the mood in the Garden with a thunderous dunk at the right time. He's going to draw a lot of fouls, so he's going to get his practice in shooting free throws.
I want to hear from someone that has watched him play and concluded that he won't be a competent shooter in the NBA.