I think it's comedy for (middle class) people who are a bit bigoted and don't have much of a sense of humour.
A few years ago I was staying for the weekend with an older very middle class couple (the sort of people who looked down on me because I'm from East London and grew up in a council house). Right humourless pair. One evening they put the tiny TV on (the more MC you are the smaller your TV, this was like a computer monitor
) and laughed hysterically through a whole episode of Mrs Brown's Boys. I was utterly baffled.