Look, it's actually quite simple. EVERY Big Ten team has left the conference footprint for at least one non-conference game in the last five years. That's pretty good evidence that every team is willing to travel some distance away for games. What logical argument can you possibly make to say that Big Ten teams will travel pretty much anywere in the country EXCEPT for the SEC? Is it the Big Ten's fear of SEC teams? I bet. Every Big Ten team, except for Penn State, has traveled all the way to the West coast at least once in the last five seasons.
On the other hand, you have three of the SEC's biggest programs - Florida, Georgia, and Auburn - that have refused to even leave the conference footprint in the same time span. Another two, Kentucky and South Carolina, merely traveled one state over.
Almost half of the SEC conference has not traveled as far as any Big Ten state in the last five seasons. What makes anyone think they would be willing to schedule a home-home with a Big Ten team? They haven't scheduled anybody else outside of their region either.
The closest we have come recently is the Penn State - Alabama series of 04-05, which Alabama postponed. Yet it's the Big Ten that's avoiding the SEC?
PLUS: COLLEGE FOOTBALL; Alabama Postpones Series With Penn St. - New York Times
By the way, Georgia has not played an OOC game outside of an SEC state since - get this -
1967 when they lost to Houston. How the heck is a Big Ten team going to schedule them?