Joining a conference doesn't have to mean your academics or reputation go south. No one dings Stanford for being in the same conference as Oregon. Or Vandy for being in a conference with...well a lot of lesser academic schools.
Having said that, the big 10 makes the most sense. Geographically, it fits. Academically, they aren't bad. ACC would have the edge there, but I don't see the ACC surviving. Maybe the big 10 will grab Duke, North Carolina, Virginia and Wake Forest to go with Oregon and Stanford. I don't see Clemson, FSU or Miami going North.
Eventually it may end up being de-emphasizing football, but until it reaches that point, big 10 makes sense. Even if we do de-emphasize football, there is still all the other sports to consider.