Not particularly a fan of Clark Kellogg, but his response to Charles Barkley about higher seeds losing to lower seeds (upsets) in this NCAA, was as articulate as any commentary that I have heard. My very abbreviated summary of Clark .......... it was a "reset' for the lower seeded teams. At one time or another during the early portion of the regular season, teams from the SEC (like Arkansas, UF, USCjr) played like top 15 contenders. Xavier, Creighton and Butler were examples of Mid-Major teams that looked like legitimate candidates for a Final Four at certain periods.
At one point during the regular season ACC "Johnny come latelys" like WF, VT, Miami, FSU and Clemson could challenge Duke, UVA, UL & UNC most any night .........but their "reset" never got pushed and they each folded up during tournament time.
As Denny said so long ago ......."parity has arrived in College Basketball". For me, these upsets are a combination of witnessing increased parity, matchup advantages, execution and some luck. Kansas performance has not been all together much different than a lot of other up and down performances.