I bet there is more truth in what you say then meets the eye.
It probably started that way in order to sell more seats to visitors. We have had some bad attendance in the past. Today, I'm guessing it has partly to do with:
A) people not wanting to give up their seats
B) more of an advantage to have the visitors fans on the other end zone during OT instead of a few on both end zones
C) less interaction between fan bases which prevents some unpleasantries. (Remember, it is a state that prohibited the ISU/Iowa game because it was too heated, that outlawed fireworks because a town burned down a hundred years ago, that fought electronic billboards for safety concerns. )