The problem at Kentucky and Kansas is that they have no natural homegrown recruiting base for football talent. North Carolina has no such problem.
I've made this point before, but it's worth repeating. Our geography puts out football program at a disadvantage. While Kansas isn't a fertile recruiting base, it belongs to KU and KSU. I suppose Oklahoma is there too, but it's still a fair bit away and Oklahoma tends to look south for recruits.
One reason, I think, that schools in our area have never been good at football is that there are too many schools for the talent base. We compete with NCSU, Dook, Wake, UVa, Va Tech, Clemson, Tennessee and that's before we even get to not-that-far-away programs like Georgia. Athens is closer to Charlotte than Norman is to most of Kansas.
Not all of those schools are good at the same time, which is kind of the point. There's not enough local talent to go around for all of us to be good at once. I mean, even ECU can nab some quality recruits out East.
This is why, I think, that the SEC and B10 schools have traditionally been better at football than basketball -- or at least one reason. In basketball, you can recruit nationally, because you only need 3-4 players per class. You can certainly recruit regionally. So being the only school in your state isn't as much of an advantage because another power school can come in and snag the best recruit in your state.
In football, though, where the class size is 20 or more, only the very top powers can fill their classes with recruits nationally. Almost everyone recruits has to recruit in state. And thus the amount of competition is important.
For instance: Penn St. They are the only big football school within 300 miles. Between OSU and PSU, they control recruiting in PA, OH, NJ and even parts of NY. So even if that talent base is worse than NC/SC, it divides two ways, not seven. In fact, if you look at the traditional powers in football, they typically come from places with few major programs, right? Alabama has Bama and Auburn and who else? LSU is Louisiana. Historically, UGa was Georgia. Nobody else in Tennessee. Texas has multiple programs but it is a huge state.
Meanwhile, SC has some the same problems NC does, and hence the lack of consistent excellence there. Clemson is the closest and they have been good recently, but they weren't so good in the 90s IIRC. USC is not good. And while UNC could probably thrive if we established ourselves as a major power, the getting there is the problem, right?