Same with the Midwestern accent. Fargo's probably the best example I can think of, or maybe the mom from Bobby's World. So when I went out to WIsconsin for University I just assumed everybody would talk that way and nobody did, on a big campus with probably a 75% in-state or neighboring state (like Minnesota or the Dakotas) student body. But my ex-in-laws, Oh you BETCHA they had it, though my ex, who lived nowhere but Wisconsin for 28 years, did not.

Same goes for the East Coast.. I didn't live out there for long enough to really think about it, but I never heard that sort of Kennedy-esque accent either.

You're not going to find a lot of people in New England who talk like the Kennedy's did. They had the trans-atlantic accent discussed in the video for the same reason: they learned it in prep school. Strictly old-timey upper crust, although a Maine accent has a lot of similarity.

I've wondered that myself and I struggle to fathom how they're profiting from it other than some sort of low level fame?

That youtube money is really good for some folks. I don't know how many subscribers or views one needs to make a decent living, but they're trying. I think its something of the internet age. People just want to quit their jobs and make a living producing youtube shows. They get to be their own boss, use their creative visions as their work, and have their own schedules. Then there's some who get filthy rich off of it.