The defense might not have lost us that game but they didn't help win it. If the offense has an off game, we lose. It's that simple. We don't have a defense like Utah's that can create opportunities or even score. No reason we shouldn't be able to have one either.
Remember that CC team played a very weak schedule to give them that record and those stats. The one P5 team they played was Kansas, and they held CC to 318 total yds. Yes, that Kansas.
We gave up 281 rushing yards on 5.2 yds/carry. That kind of defense isn't going to win you many games.
I'm not saying the defense lost that game because the offense wasn't very good either. Defense didn't do much to help win it though.