They do not care that someone called John from Watford who loves flying and has £80k of debt is not earning to his colleagues potential. They simply see John as cannon fodder for their 4-5 year plan before they go and manage the next 'blue-chip' company.
The snag is that suitably qualified Johns keep queuing up and beg to be used as cannon fodder. Until that stops, I can't see why any Board should not go down that route.