I’ll admit the SEC is down this year, but it’s not nearly as bad as you say it is. The difference is that there is one clearly superior team atop the conference, rather than the usual 3 or 4 jockeying for that position. Teams like LSU and Georgia have regressed towards the middle of the pack. However, past doormats like Vandy and Kentucky have gotten significantly better.
The Big Ten on the other hand, is much worse than everyone is giving it credit for. The reason they have four top 10 teams is because they get to clean up against Minnesota, Illinois, Indiana, Michigan St., Iowa, Northwestern, Rutgers, Purdue, and Maryland.