No, I don't think we're being too hard on him. I hear so much about how good the talent is in Iowa's offense this year, and guess what? We're still one of the worst in the country offensively, and that's against an easy non-conference. I can't believe things are going to improve when the schedule gets more difficult.
3 years of Greg Davis's offense, and 3 years it's been horrible. When he turns out a good offense, then I'll reconsider this notion. At least KOK had some decent years, and the scoring offense was at least "top half" most years. Yeah, his offenses weren't usually what I'd call GREAT, but they at least seemed half-way competent more often than not. I can't hold 1999 & 2000 against him too much since the program was in pretty rough shape, and things improved pretty quickly after that.
The rushing offense... That disappoints me. I thought KF was supposed to be this offensive line guru, so I would have expected a little better results in our ground game. But if you're running into a stacked box all the time, then I suppose that's moot point.
None of this is to say that I think KF can't (or shouldn't) share some blame here, though. I have to believe he has a lot of say in how the offense is run, and average to just plain bad offense has been the norm. Being an ex OL coach, I would think he would care more about the offense than he seems to.
That said, I don't think Greg Davis's scheme is going to work and was a bad hire. As Jon said, there is NO vertical threat from that offense, so it's like being in a goal-to-go situation all the time.
As others have said, KF hired an OC that would run the type of offense that he wanted to run, not necessarily the BEST hire.