It exists only insofar as naive children internalize and ape what they see on TV. There is no reason whatsoever that a bright child shouldn't enjoy sports, except the Disney channel tells him he must choose between reading books or exercise, when there is plenty of time in the day for both. And insofar as it discourages smart kids from exercising, it's a clearly harmful stereotype which you should refrain from reinforcing.
Real life is not a 1980s teen comedy movie, no matter how comforting out of shape engineers may find the notion.
Hollywood is a reflection on culture, not the other way around. They just make what people want to see (it's a business, after all).
Anything else is mindless conspiracy theories. There is no secret cabal pushing culture to the masses.
It's so bizarre to observe normal humans and businesses (and how organizations completely fail at any meaningful scale), and then to turn around and assume there is a hyper-intelligent, hyper-powerful secret society running things.
Instead of blaming Satan, now we have boogeymen from conspiracy theories to fulfill his role.
Real life is not a 1980s teen comedy movie, no matter how comforting out of shape engineers may find the notion.