My god, I remember when the Big 10 was actually a decent conference in football/basketball, what happened in the past 10 years?
Everybody got better at recruiting around the nation across the board so the gap was narrowed. Plus a lot of college football systems changed to take advantage of certain aspects that came up, like the new systems that work the passing game unlike before, and the Big 10 never adapted either because they didn't know how, didn't have the personnel for it, or were too tradition bound. Plus now that there is a lot of quality programs out there now from even the colleges that aren't historic powerhouses having to play and live in a colder climate sucks for a lot of the athletes when some of them can easily get recruited somwhere else.