I'm not defending Bo, as I agree many of his schedules were weak - but our schedule last year was not tough by any stretch of the imagination. Especially since every team with a pulse (Iowa, Michigan State, Wisconsin, Northwestern, BYU) we played at home. Our Big Ten road schedule was a joke (Illinois, Purdue, Rutgers, Minnesota).
It's tough to find SOS rankings, but according to teamrankings.com we had the 50th toughest schedule in the country, just above Iowa, Syracuse, and Memphis. That site has Bo's 2009 schedule as the 5th toughest in the nation (finished 10-4). Only once did Bo have a SOS lower than 50 (2013, when he should have been fired).