There's no value in that combo. The Big Ten makes a lot of money and adding those two together wouldn't bring anything groundbreaking for growth or more money.
To an NU fan, KU and ISU add a lot of value.
Two regional teams that have history with Nebraska.
Games that are easy to travel to.
Most importantly, two teams that are unlikely to take over Nebraska in the B10 pecking order.
Why exactly are WE wanting teams with more prestige that bring a little more cash that is going to be split 16 ways? The difference between adding Notre Dame or Iowa State probably won’t amount to more than a couple million on the bottom line for each team in the conference, but adding a team that is probably likely to lower Nebraska’s standing in the conference IS bad for the fan experience and also the athletic department’s bottom line.