You make a good point but I don't think it is the one you are trying to make. Yes, turnarounds don't have to take 5-10 years like they used to and teams like Indiana have shown they can take only 1 year.
But, this point does not necessarily mean that you have to get a new coach. Most of the time we see coaches get fired because of glaring and systemic weaknesses that make it obvious they cannot manage and run a quality football program. So the new coaching staff can come in, establish a culture, clean house and start from there.
Iowa's case is so unique though in that the culture is solid and the management of the program overall is consistent and established. PP would be a top candidate for any elite program that that was only a defense away if he was available. Iowa's special teams are as good as anyone's in football over KF's tenure. The offense has been awful, but, there is a new OC in town and to me he is very refreshing, open, honest and I think he knows what he is doing AND it is pretty apparent that KF is allowing him to do what he wants to do and say what he needs to say. I think the S&C program took a hit after Doyle, but, it still appears to be very good.
My point is that if Iowa can get the players then this staff can coach them. I am confident PP would build a national championship level defense with the players, he has done it before. Same with LW. I really like TL and if he had some elite players I think he would know what to do with them. And the standard of run the ball, stop the run, play solid special teams and don't turn the ball over is still a winning formula.
So to me this whole thing has nothing to do with coaching, but instead, has everything to do with recruiting. So unless a guy can come in and just recruit better without any additional resources then I don't see why anyone would think that logically it would be much better than what we have. If a person just wants different, I understand, that is their opinion. If keeping KF and the current staff is inhibiting fund raising to recruit and retain these players, then I agree everyone should look to move on. But I don't see any evidence of that either.
I am just speaking for me, I am not afraid of life after Kirk, but, non-emotionally and pragmatically looking at it I would rather see what TL can get in here after being on staff for a full year and how PP will re-load this defense than to see a new coaching regime take over. Atleast for the next couple of years.