Disagree. All four losses can be attributed to losing the Turnover battle--not just the number of them, but the circumstance of them: in the Red Zone, while backed up inside your own 20, etc.
I've said it before, for all the other convoluted things that have happened (as you outline above, the incredible amount of injuries this season, no production from the WRs, etc.), but don't commit those costly turnovers, and there are 2 or 3 more wins on the record this season.