Again, I'd disagree. At the beginning of the season, yes. The second half of the season not so much. A lot of what you might think of as the tackles getting beat is our QBs trying to scramble out of the pocket instead of stepping up as @BigRedBuster alluded to with QB in the passing game.
I just rewatch the Purdy plays again from the other page, and for the Iowa game I think the tackles got "beat" once, and even then it wasn't bad. Benhardt had a really difficult assignment when Iowa was showing 7 and brought 6. He had to take a guy in a wide 9 stance and just kind of got in his way a bit. It was ugly, but Purdy scrambled out to that side and completed a pass for a first down. I'd probably up my grade to a solid B on the rewatch.