Sorry to jump in here. Not trying to be argumentative. But to anyone observing the games all season it is fairly obvious the team just hasn't been playing as well since, probably, the MSU loss right after the winning streak. That was a tough one to drop and one that was right there for the taking. We just didn't close it out.
Sure but how many other teams are "playing as well" as we were then? Since that loss we've dropped 3 games. In that same time span:
Iowa St. has lost 4 times.
Kansas has lost 4 times.
Houston has lost 3 times.
UConn has lost to Creighton and Marquette.
Nebraska has lost 3 times including a 20 point loss to UCLA and a loss at home to Iowa.
MSU lost twice, one of which was a 21 point loss to Wisconsin (they also lost to Minnesot right before they beat us).
UVA lost to a bad FSU team and lost by 26 to Duke, and scraped and Wake Forest and VT teams.
Gonzaga has played nobody and still found ways to drop games.
Purdue has lost 4 times, 3 of them at home.
Texas Tech just lost their last 2 games, and 3 games totals since our MSU loss, none of them vs a ranked opponent.
So really, applying the standard you're putting on Illinois, is anyone outside of the 4 likely 1-seeds actually "playing well" since early February?
The fact is there are exactly 4 teams that are hot right now, and Florida hasn't really been tested and AZ has looked vulnerable at times. At least 4 teams outside that top 4, i.e. teams that haven't been playing nearly as well as we were during that winning streak, are going to make the Elite Eight and at least 12 such teams are going to make the Sweet 16.