I was going to say his sub .400 shooting percentage but after looking it up its back up to .413 this season.
Well people always point to his sub .400 shooting percentage but if you looked at how he played during the Olympics, you realize how good he could be if he gotten some real help. All he needed was a side-kick and he would've been fine, but that's not gonna happen and he'll always be forced to take the last shot, the tough shot, the shot that he have to take because the shot clock is running down.
In all seriousness, the answer is no. I've been to 4 Sixers games in the past two weeks, and I can tell you that AI can get past his man and into the lane whenever he wants. His first step is just that good. Problem is, he doesn't always take smart shots. He's his own worst enemy in some ways ... plus the fact that he's never really had any help.
Cat+ did a fine job on him last year, IIRC. They were really shutting down the SGs for a stretch there though, and forced TMac to look horrible a couple of times as well.