He's an actor - and a fairly good one. This of itself is no reason to expect him to be intelligent, articulate, opinionated, charitable, angry, sad, spiritual, thrifty, extravagant, hedonistic, calvinistic or anything else.
I didn't see the programme, but if I had, rather than take disappointment from the man's perceived limitations, I would prefer to take the view that it was great that his limitations have not held him back from expressing his acting talents.