What we need to consider is that the club actually has a better idea of these players than we do, let's be honest here. From what I see Ranocchia is being kept in high regard as he's being mentioned by Allegri almost every time he speaks of youngsters and Agresti also says Ranocchia is his favorite while he obviously has some insight in the club.
The comparison with Beruatto is unfortunate in my opinion as he remained in Pisa that's actually almost at the bottom of Serie B while Ranocchia is fighting for his place with the likes of Rovella, Sensi, Pessina. What's more, I heard he's been fielded higher up the pitch which is not his natural position so obviously the coach has faith in him.