While coaching choices are part of the problem, Nebraska's woes go beyond coaching. The move to the Big 10 is a major part of the demise of the program. While they were in the Big 12, they were located midst the teams in the conference. One good coach, Bob Devaney, got them started to elite status and they stayed there a long time, thru the Osborne era. They had recruiting success in Texas and other areas rich in talent. God knows they needed it because Nebraska has very little. As they stayed high in the rankings, they could draw individual talent from all over the country.
Then they join a conference where most of the power and interest is located much farther away from home base. Kids in that part of the country stopped thinking of UN. Suddenly, Oklahoma State, TCU, Baylor, and the rest of the league drew all the attention of recruits. Kids in Big 10 country look to UM, OSU, PSU, IA, WI (and us) for good programs. Nebraska is now on par with Kansas teams. They have no talent pool to draw on. Think they are done. I think the same thing happened to PSU. They have been lucky that Michigan has struggle or else they become another Nebraska.
When people urge ND to join a conference, I cringe because of the above. We have recruit nationwide. That would end. We localize recruiting area to where ever are our conference would be in, whether Big 10 or ACC. A couple of bad years and we fall in recruiting level to the lower rungs of the conference, like Wake or Duke or BC in ACC or Minn, Ind, PU, Rutgers in the BIg10. Once that happens, we would be done. We can never be in a conference, even if it makes it more difficult to get into the NC playoffs. Better to push for expansion of teams.