He simply is not ready yet, he probably will be ready someday. But the Rooney Rule-prompted interview requests last year, combined with Kraft (naively) pumping him up, have created an unrealistic situation that could backfire badly on Mayo and the franchise.
I can understand Kraft's sentiments about Mayo but expressing them publicly was premature. He likely figured BB would comfortably surpass Shula's record, groom Mayo in the process then retire/ride off into the sunset. Then the 4-13 disaster occurred throwing a monkey wrench into the works, compounded by Vrabel coming available. If Mayo gets the job over Vrabel, Flores and a few other much more qualified candidates I will not be happy.