I think most people do this to some degree - we are all affected by negative factors in our childhood which shapes the way we act in later life. So I wouldn't say he's a "schtick", it was a coping mechanism that has worked in his favour - I don't think that's a negative thing, it's not like his ultra-poshness is badly affecting anyone else.

I went to private school in the UK - there are loads of people like him.