I think the rationale regarding KC was, what else is out there? Coming back to the same system, Kubiak, and the overall surround was analyzed and thought to be as good or better than before.
KC makes some bone-headed plays and he aint mobile, we know that. But with the right surround?
Vikings thought they had the pieces on O and screwed-up regarding the OL again then Diggs forced his hand out of here.
Then you've got all the Covid crap and the D draft capital gone in the blink of an eye + Barr lost for season.
It sounds like a bunch of excuses for KC, I think it's rationale for this conclusion: Life happens AND the Vikings have not done what they needed to in order to give him the best chance at success. The Vikings have a league avg OL on their very best days and a D that cant keep em in games very well anymore.
The whole thing imploded this off-season and their window is closed in 20. Maybe more competitive in 21.