Exactly how bad is our OL? I think these two stats tell everything we need to know.
We have played 5 opponents. If we calculate their average tackle for loss and average sack per game (sans the Michigan game) and add them together, you get 25.8 for TFL and 6.25 sacks. This is what our opponents have done when they were not playing Michigan.
If you add up TFL and Sacks for the games that they played Michigan, you get 38 for TFL and 16 for sacks. Simply put, our opponents (defense) registered 50% more TFL than average and almost 3X number of sacks than average against our OL.
That is a tire-fire level badness. You don't need to look any further on why our offense is so bad.
P.S. There was a question about this stat not being tempo-free. I went back and checked and our opponents faced about 15% (at the most) more offensive plays than their average against Michigan. So adjust above numbers down by about 15%. It still does not explain that our opponents are registering 35% more TFL and 2.5X more sacks than against other opponents.