I think they're looking at their records and seeing pretty different strengths of schedule. Minnesota's best win was over Nebraska, and the remainder of their wins pose questions about how good they really are--close home wins over Rutgers and Purdue aren't impressive. Their losses do the same: Iowa smoked them, and they lost at mediocre Cal. This is the kind of team that will finish somewhere between 6-6 and 8-4, but be thoroughly mediocre regardless. I guess 8-4 would likely include wins over MSU and Northwestern, so that would elevate them to slightly more than merely mediocre--but probably not a lot.
Conversely, MSU may have a poor record, but with the exception of the home loss to UCLA, they've performed like a decent team that has been playing better teams (Indiana, Michigan, USC, and Nebraska). In each of those games they were at least able to score points, and none of their opposition completely dominated them (unlike a certain team that I cheer for, which has not only lost a lot, but has looked uncompetitive in most of those games). This is the kind of schedule that results in probably missing a bowl game, but not really being any worse than Minnesota.