Mainly because the game between the two is no longer a game, but more like a crop harvesting contest, as evidenced by the new Cy-Hawk trophy given to the winner.
For we all know, nothing commemorates a victory over a rival (are they actually rivals? Has Iowa State won enough to justify using that word?) in which both sides beat the hell out of one another for three-plus hours like art of a stereotypical, young American farm family gathered around a basket of corn.
HARVEST AWAY, IOWA.