It seems to me that the issues on offense are threefold:

1. Lack of consistent effort
2. Lack of precision
3. Lack of personnel

While 1 and 2 could be ascribed to the OC, I feel it's probably more attributable to the HC and the culture shift. I think we knew coming in that Detmer wasn't the disciplinarian, that someone else needed to take on that role while Detmer handled Xs and Is.

3 is both regime change and the shift in philosophy (leaving mismatched personnel for the system) as well as injuries. Detmer has had to dumb down the playbook and shift to more of a spread system over the course of the season to deal with mismatched personnel. Detmer hasn't been perfect, but I don't think he deserves all or even most of the blame.