Sometimes one's perception is altered by what one expects to see....
Bingo! The ref's read the papers too. They hear if one team has a good o-line and the other team's d-line is struggling. When the defense isn't getting penetration or plugging holes, they don't bother to take a closer look to see if someone is getting held. I don't think it's intentional, but decades of bad football have caused the general populace to figure that if ISU isn't making plays it's because they're just bad.