Basically we're asking Mickey to stay on at Nebraska in essentially the same role he had at a more prestigious football program, LSU. Maybe even less, as I believe he was also the assistant OC at LSU.
Mickey is more Louisiana home boy than he is Nebraska home boy, so I'm guessing Nebraska was always a stepping stone, not a lateral or sentimental move. Although his record this year doesn't exactly speak for itself, I do believe Mickey successfully raised his profile. If Nebraska made a mistake not hiring Mickey as full time HC, another P5 program will take advantage of it.
If he stays on staff at Nebraska he will do all the right things, as that's the man he is. If he leaves for an HC job at a lower tier school, or a staff position elsewhere, there should be no bitterness on his part, or hand-wringing from Husker fans. It's all pretty logical and above-board.