You're suggesting extreme, unmitigated incompetence the likes of which is just as unlikely and spurious as the claims that our offense is secretly the best in the NFL.
So, instead he should design every play for Spiller to be bounced to the outside? He has to go up the gut every one in a while. And when he does he gets 3-6 yards...consistently. It's the plays that he's moving laterally behind the line that haven't worked.
Plus, there's a lot of revisionist history here as to how flawlessly Chan used Spiller last year, when a.) everyone was SCREAMING for him to use Spiller like Hackett does now and b.) he used him in dual sets with Freddy about as often as Hackett has also. See: Easley, Marcus.
It's just you.