That's B.S. There are plenty of games we'd have lost if he wasn't for him.
As far as gratitude, where are you finding evidence that Akrum Wadley doesn't appreciate Kirk Ferentz? I've certainly never heard him said anything that would indicate that. Kirk Ferentz actually hated his running style and was much more sold on Daniels. If anything, Kirk should admit he was wrong about it.
And if you're saying gratitude would be staying another year for the sake of the Davis/Ferentz 1-2 punch offense, you're a bigger dumb ass than I would have thought.