Hear me out here...
Leach was great but he was great at smaller programs like Tech, Washington State and pretty good at Mississippi State before he passed. You put him at a school like Texas, Alabama, Michigan, Ohio State, USC, etc. and I am of the opinion that he could not handle everything that needs to happen for a HC to be successful. Where am I going with this? I think Lane Kiffin falls into that same category. He's been really good at Ole Miss. He had only one year at Tennessee so we have no idea how that would have turned out but I suspect it would have been good. He failed at USC and coaching the Oakland Raiders.
I realize that his time at USC he was much younger and probably immature. He is wiser today but still has tendencies to be an ass. If I were Alabama I would be very cautious in my approach of going after Kiffin. The risk is not worth the reward, IMO.