After Pelini, Mike Riley was there almost 4 years:
https://en.wikipedia.org/wiki/List_of_Nebraska_Cornhuskers_head_football_coaches
It's an extremely rough job at NU. They expect NC's, but are in a rough location with few in-state or even surrounding blue chip recruits, they play in an ice cold area with very little redeeming qualities besides being really really rough (It makes Oklahoma weather look like paradise). You can't just go out and out-train/out-steroid other teams any more like they used to (along with many other blue bloods at the time) and so you have to land elite talent to get to the level NU fans expect. Kids see TV and they see trendy uniforms, flashy offenses and all the jokes/brags on social media (where NU is not going to be on the good side). They don't know of NU ever being good and most probably don't even remember or know who Scott Frost was as a successful HC. NU was historically great, but not in this millenium. Just a few Big 12 runner ups to OU.
NU is this weird team that suddenly joined the Big Ten, despite their rivals, and plays those teams and so they'll potentially get recruits from those areas, but they lose to those teams and have for most recent past (They have effectively zero "brand" in Big Ten except being an under-performer vs hype). Their best sell to elite recruits is that you can potentially play early and train to get drafted. And
maybe NU will compete to get to the Big Ten CCG someday where Ohio State will crush them, but probably not because Iowa and Wisconsin almost always beat them (and now Minnesota who landed the real "Scott Frost" in PJ Fleck).