Some of the problem is similar to OU. Instate high schol talent is woefully lacking. And it is harder for KU when KState has Snyder. There are typically less than 20 high school players in Kansas who get D1 offer. That includes lower tier schools. Some years,, that is less than a dozen.
Kansas has always had to look elsewhere. They were really good in part of the 60s. Their best player ever was likely Gale Sayers. He was from Omaha and recruited just before Bob Devaney turn Nebraska into a national power.
They got lucky with a couple of brothers who played at a small instate school. I believe that Junior and John Riggins played 8 man football. 30 years later, Glen Mason made KU football better than decent. But Kansas lost him in really a lateral move. OU being down in the 90s helped them with that. Bob Stoops is bad for KU football.
I also think that Mangino was double trouble. He was abusive to players when he was at OU. Likely was before, and certainly was after. But he split the few money people at Kansas who care about football. Some thought that brow beating players was part of the job description for most football coaches.
Some thought he was an embarrassment when all that became public. I suspect that most KU fans are perfectly happy to be a top five national basketball program and while they love it when football is good too, it is not a passion.
When you lose games to DII schools, it can get hard to recriut. There is one other factor. In football, KU is a stepping stone school. A lot of factors make that unlikely to change. So even if they find someone who could make them a winner, he would be unlikely to stay. The irony is that Mangino was maybe one who would have.
They have paid good money for the guys after Mark, who seemed to be good hires. They were not ... at least not in Lawrence. Charlie has Super Bowl rings and the good wishes of Tom Brady. Turner Gill was on lot of search lists with a high school background in Texas, a Nebraska pedigree and a good record at a place that had not won much before him.
They could not win there. Once you become an annual last place team, it takes somebody pretty special to turn that around.