UConn was a different story.
Zissou "advocated" for a UConn program that just had 3 straight losing seasons in the AAC.
That's a different scenario than an in-tact Kansas, who is not far removed from a Final Four, and who just saw their conference mate (Baylor) with the National Championship in a blowout over the other team you're pimping, Gonzaga.
The Big 12 is also not "a top 4 conference like the NBE." (The Big 12 is the Top 1.)
Kansas is a founding member of the Big 12 Conference (one of the Original Big 8). Why would they leave the Conference they founded and their rivals at KSU, Baylor, OSU, ISU, etc, to be an outlier in a far-flung NBE.
The NBE has only been around for 8 years, and barely has a lengthy history with the 10 founders. Why would Kansas see any stability in a fledgling league?
Big East Conference - Wikipedia
Perhaps the OBE would've had more lure with Notre Dame, Syracuse, Pittsburgh, Louisville, but that ship has sailed.
Big East Conference (1979–2013) - Wikipedia
(This is about the former league that played from 1979 to 2013. For its successor football-playing league, see American Athletic Conference. For the current league of the same name, see Big East Conference.)
Why, why, why? The answer is still money and a stable path forward to a basketball-first athletic dept.
Founding members of the Big 8 - only Kansas remains.
Final members of the Big 8 that founded the Big 12, only four remain, Kansas, Kansas State, Iowa State, and Oklahoma State. “Although the Big 12 was essentially the Big Eight plus the four Texas schools, the Big 12 regards itself as a separate conference and does not claim the Big Eight's history as its own.” The higher football profile schools were poached - Missouri, Oklahoma, Colorado, and Nebraska.
Of the four Texas schools that joined the Big 8 schools to form the Big 12 in the late 1990s (17 years after the start of the Big East), the 2 highest profile programs were poached by the SEC - A&M and Texas.
There is certainly a perspective that Kansas has been “left behind”, and their next TV deal will show that. It does remain a solid basketball conference, albeit in less attractive markets than the Big East.
Nova joined the Big East in 1980, year 2 of the conference. Of the original first 8 Big East lineup, we today have Georgetown, St Johns, Providence, Seton Hall, UConn, and Nova. Only BC and Cuse are gone from the first 8. 6 of the first 8 are intact in the Big East today.
(For those keeping score on religious affiliation, there were 2 schools in the original founding members that were not Catholic, and there are 2 schools in the conference today that are not Catholic. Also, there was one public school in the founding members, and the same one public member in the current membership).
The new Big 12 has twice as many former C-USA programs than the Big East. Kansas has good reason to feel it is in a diluted Big 12.
Since the CR with the American - Big East split, zero teams have left the Big East.
I think you were touting the founding member angle in the perspective of stability and tradition. The Big East has as much claim to its origins as any conference, and more so than the Big 12