After first of all pointing out that the Big 10 has three traditional powers: Ohio State, Michigan and Penn State, i.e. three schools with stadiums big enough to place them in the top tier of attendance (Butts = Money + TV, Money + TV = Recruiting Budget + Facilities, Rct Bud + Fac + Tradition = Championships, Championships + Tradition = Fan Base That Travels, FBTT + Championships = Big Bowl Bid.)
The Pac 10 has one such program and even that program has trouble getting butts into seats. The Big 12 has two: Texas and Oklahoma, The ACC and Big East combined have 1. The SEC has six: Alabama, Florida, LSU, Georgia, Tennessee, Auburn.
When you take Michigan out of the picture the Big 10 begins to look more like the ACC and just as we yell and scream about any ACC/Big East team that qualifies for a BCS Bowl, you can bet that fans of other conferences will be bitching up a storm when Ohio State or Penn State gets a top tier bowl by beating a 7 and 5 Michigan team. "Just who TF did they beat? Akron, Troy, Indiana, Purdue, Northwestern, Minnesota, Illinois... when did they play anybody good?"
If you think I'm exaggerating just go back to the November - December postings for the last several years (including some of my own) concerning SOS and how Notre Dame, Big East or ACC teams got into key bowl games.
Michigan State, Wisconsin, Illinois, Iowa, Illinois, Minnesota and Purdue don't have a 100K stadium, have never sustained a program that wins or competes for the conference championship across a decade, much less two decades and therefore don't generate TV interest, don't bring in the same revenue levels, don't "carry" Indiana and Northwestern financially the way OSU, Michigan and Penn State can and have.