Based on what tells you he doesn't have it? Granted, his stats were not great, but he did have some good moments and did play well in the preseason when he was allowed to open things up. He played for one of the worst NFL offensive coordinators ever with Canada, and, on top of that, didn't know how to develop the QB. Tomlin isn't exactly a QB whisperer either. Tomlin was lucky to have prime Ben fall into his lap when taking the job.
Kenny may not ever be the guy, but I'll give him some more time to develop under a different system. I wish him well and hope he does well. Now, the Steelers need to figure out how they are going to play offense for an entire season with a 35 year old QB that has not been at the top of his game even before getting traded to Denver and one legitimate NFL caliber starting WR on the team with no center.