I was going to do a big old post about this debacle - but I think most of what's wrong with True-May's statement has already been adequately covered by the article.
I just want to add one little thing.
Culture and "the media" plays a massive role in, not just reflecting societal norms but creating and enforcing them. The images we see around us every day help to form our attitudes and prejudices. If we see a sleepy little English village on TV, and the Kumars on the corner and Mr Smith the (black) GP, are an integral part of it, then we are going to start seeing this as normal - and crucialy as acceptable. And can't we all agree that this is a good thing? Ethnic minorities are, and have been for a long time, part of England, and valuable contributers to this country. They have as much right to be a representative part of it as closeted, bigoted, middle-class, white dudes.
I don't care if the countryside is still mainly white* and MM is "just" a reflection of this - The Media has the opportunity to challenge social norms and the duty to be inclusive.
It all comes down to this: Do we want to challenge racism in our society? Yes? Then include non-white people in our culture to the extent that we want them included in society.
*Actually, I do care; I would love it if rural England was seen as welcoming to people of all colours and creeds, but that wasn't my point...