First of all, there should be a caveat on this site that we no longer talk about the "dark era" of football when talking about how "competitive" we are now. That "dark era" ended 33 years ago. It is no longer relevant in this day and age of money, facilities, television revenue, etc. We are in the Top 20 in athletic department revenue and we are in arguably the richest, most successful conference in the country.
With that being said, I think the majority of people are happy with Ferentz's body of work over the past 13 years. 2 Big Ten titles, 2 BCS bowl appearances, a 6-4 record in bowls overall, Top 10 in NFL players on active rosters and not a sniff of sanctions or improprieties during his tenure.
However, success certainly breeds expectations. And if there is one thing that I can point to that tends to stick in fans' craw, it's the unexplainable losses to teams that had no business being within 2 td's of us. A few weeks back I did an analysis of KF's record against 3 tiers of teams....teams that finished with 8+ wins, teams that finished with 4-7 wins, and teams that finished with 0-3 wins. Since 2001, we have the best record of our "peers" in our conference (MSU, Mich, Neb, Wisc, and PSU) against teams that finished the year with 8+ wins. However, other than MSU, we have the worst record against teams in the 4-7 win range....by quite a large margin. Mich, Neb, Wisc and PSU win those games at an over 85% clip. We are just under 75%. Since the majority of games are against teams in the 4-7 win range, a 12% difference over 11 years is HUGE! It's the difference between avg'ing 7 wins per year and avg'ing 9 wins per year. It's the difference between going to a so-so bowl and going to a BCS bowl. Those losses have to stop if we want to take the next step. We have the money, we have the facilities, we have the conference affiliation and we have the players (as evidenced by the number of NFL players). What we need now is better game day coaching and more timely risk taking.
I look forward to seeing what KF and the new coaches can do moving forward!