Not true. The defense shut down Colgate completely, after the first drive. Forced a ton of punts -- and no signs that Colgate wasn't trying. That Colgate offense returned most of its starters from a team that scored a heck of a lot of points in the second half of 2015 (granted, at a lower level).
We have 9 starters back from a defense that was not that bad, last season, against teams like LSU, Clemson, Florida State, Pitt. It wasn't good enough, but it wasn't horrid. We lost the DEs, but in every other unit we should be better this season -- and it did not look that way last night.
Too alternatives -- Jackson is superman (and I think he is, plus he has a strong OL, and several outstanding weapons); or our defense regressed under the new staff.