I am guessing that it is the students that are rushing the court? Indiana's last NCAA title came in 1987 - before most of the students were even born. They don't remember Keith Smart or Steve Alford.
Those students that have been there 4+ years (Seniors, if you will) have endured the ugly end of the Mike Davis era, good success and then a massive scandal under Kelvin Sampson, and then a one win conference season under Coach Crean last year. I can see how they are getting excited over victories against unranked opponents, championship banners in the rafters be damned.
Another way to look at it, as Gopher fans, is as a sign of respect. Would they have stormed the court after beating IUPUI? Probably not. Will they storm the court after beating Iowa this year? My guess is no as well. Minnesota is viewed around the conference as one of the best teams in the Big Ten with one of the best coaches in the Big Ten. In an odd way, it might just be a compliment.