Honestly, I'm beginning to wonder if the only reason he hasn't been benched yet is because Doc is afraid to admit that it was a failed experiment.
I mean, Doc has stuck with him so long in the hopes that he would turn it around, and with people all around him saying that Terry was done. Doc may be worrying about how he'd look finally admitting defeat.
Hell, Doc could even have secretly become obsessed with the turnaround of Jason Terry, and be fearing that the moment he finally benches him is the moment he would have turned it around.