I really don't agree with the above assertions AT ALL!
Iowa rotated guys on the DL with pretty great frequency. Both Binns and Daniels saw a lot of action ... and Daniel even saw a good bit of positional action too. Frankly, that is MORE substitution on the DL than we usually see.
As for coaching ... a lot of the coaching was pretty darn solid. The coaching was frankly one of the reasons why Iowa stayed in several of the games. That's not to say that mistakes weren't made ... however, when things go right, much of the credit goes to the players for their execution. When things DON'T go right ... much of the blame is also ATTRIBUTABLE TO THEM. It's a little thing called accountability.
Whenever you lose close games ... the outcomes could have hinged on any one of dozens of different things. One of the biggest things that hurt Iowa early in the season was absolutely terrible special teams play. As the season progressed ... it seemed that it was then largely injuries and emotional deflation that brought down the team.