The last assistant OU hired to lead the basketball program was Dave Bliss. 1975, I think, without looking (I looked the other day). Maybe 1974. It does seem like our program is above it, for the last 50 years anyway.
I'd argue that football and basketball aren't nearly the same when it comes to how coaching hires work and/or how things work in general.
It's very, very rare for an college basketball assistant to jump to head coach at the high major level. Maybe 15% of head coaches were hired, at this level, who lacked experience. Assistant - small/mid major HC - big program HC. That's the customary ladder for coaches. Several of the 15% I'm referencing are coaches like Jon Scheyer who were groomed/picked to replace retired coaches. And out of that 15%, over half would be deemed failures (if we're counting Eilert at WVU who has had an opportunity to get the job/win). I'm not as data-driven, or smart, as our man
@TEvans4Three...maybe he has better data on this stuff. I'm very basic in nature, lol. Roughly though, 7-8% of high major programs are having some success with a HC who previously lacked HC experience. The odds are against Kellen. That's sort of my overall point. It could work but again, it doesn't feel like a safe bet.
Meanwhile in CFB, it's customary. OCs/DCs are essentially the head coaches of their specific units and that's just the way we view it, especially if the coordinator calls the plays for their units. The next logical step is HC. You could maybe equate a football program hiring a RB (or any singular position) coach as the HC to a college basketball program (again, high major) hiring an assistant. I don't have those stats, though.
I saw you say Kellen would be like hiring Venables and I disagree. For the better part of two decades or so, the top 3 DCs have been Kirby Smart, Nick Saban, and/or Brent Venables. Arguably. Saban and Smart have been head coaches for a long time, obviously, with Saban hanging up the whistle now. Brent could have been a HC a long time ago and finally gave in/accepted the OU position. He has three national championships as a DC/co-DC. Kellen is a good assistant but he isn't in the same stratosphere as Venables. And let's be honest, I "love" Coach V as a fan, great man, but his time hasn't been exactly deemed an enormous success, yet.