I honestly don't know why they'd leave. They have a clearer shot at a CCG appearance where they are every single year. It's not like it will get any easier if they go to the Big Ten, and if the Big Ten goes to 14 or 16 teams, it makes it even harder. I mean their biggest road blocks are Kansas State and Missouri. I love KSU, but seriously, come on.
Some schools will care about academics, but my personal feeling is that Nebraska doesn't give a damn. Their academic and athletic donations hinge upon how well the football team does, and their football team will be much better in the Big 12 than the Big Ten.