I bet St. John's has as many top 50 wins as does Illinois. Speaking off the cuff, but just saying, Illinois is junk and deserved to not be in the tournament. You can't win that many games against the top 50 and still have an RPI as awful as 75.
ETA - that should tell you something about the Big 10 this year - Illinois only played eight games against teams in the top 100 of the RPI. Meanwhile, take a similarly awful Big East team in ST. John's, and they played 13 games against top 10 RPI squads. Anyway, if you don't play anybody good, you can't beat anybody good, and Illinois stinks. End conclusion.