I think "it" is simply ingrained in all of us, it could be Miss State or South Carolina in that group versus Michigan. The "labels" carry weight. Each of us admires when the underdog program does well, but we think/suspect/believe it's a fluke and not really real.
And in the past, that has more often been the case than not.
But, if A&M or Florida met IU or NW on the field, they'd be large favorites in reality.