It's not about recruiting and never has been. That's just an easy answer. They do it because it's a Cool Thing. Some people really like Cool Things. Dave Brandon, the players, and select members of the fanbase spring to mind. Some people don't like Cool Things, and other select members of the fanbase spring to mind. It's as simple as that.
"The University of Illinois is also in turmoil. The university sports an Interim Chancellor, an Interim Athletic Director, and an Interim Football Coach; the game will be played at Soldier Field, making this an Illini Interim Home Game."