Brian,
I think they completely ignore the few millenia of glaciation that sculpted the landscape and the poverty of soils it left behind.
Instead the viewer is lead to believe that some sort of golden age was lost where upright crofters tilled the good earth in harmony with nature.
The program suggests that if they could be persuaded back, all might be restored.

Fat chance of them leaving the comforts of Glasgae for a peasants life on the crofts.....at least not until the subsidies from the ever wicked sassenachs south of the border dry up!