While I agree that they have been going to him too often and he needs to learn to kick the ball back out sometimes, I don't agree that his low post game is that bad.
If I'm not mistaken, he's either leading the league or close to it in FG percentage. He's added a decent little turnaround. Resently I've seen him make some nice drop step moves. He's even hit some foul line shots. Keeping in mind that he's only 25 and had no offensive game when he came into the league, I think he's devoloping okay.
He really just has to learn to make his move quicker or kick it back out if it's not there.