A lot of these teams that aren't very good like Kansas, Minnesota, Indiana, etc. are still a lot better than they show on a weekly basis. Few teams are really as bad as those teams have looked for much of the season. The real issue is that once they figure out early in the season that they aren't any good, they tend to fold easily when the other team asserts themselves. We saw the same thing with some of Mac's teams. We may have been competitive in a loss early in the season, but as the losses piled up we stopped being competitive at all.
Look at Iowa-Minnesota last week. Minnesota found out early in the year that they suck and basically quit trying to stay competitive. Then Iowa goes up there, doesn't assert themselves early, and Minnesota realizes they still have a chance in the 4th quarter. Not only did they come back to win, they also put up a fight at Michigan State yesterday. Motivation is a factor.
Kansas, like Minnesota, is mentally weak. Their season started off promising with wins over McNeese State and Northern Illinois, and they were only down a touchdown against Georgia Tech at halftime. Then Georgia Tech blew them away in the second half. KU led Texas Tech 20-0 in the next game, but Tech came back to win and that was basically it for the Jayhawks. The next four weeks they played four really good teams and more or less quit. ISU failed to pull away by hurting themselves with turnovers and penalties and KU stuck around. Since Kansas came up short, expect them to get annihilated the rest of the way except maybe the Mizzou game because it's a rivalry.