A quote shared by a friend of mine on Facebook...

[Divernan]

36. Talent, yes, but your examples are limited to comedic programs

(and no fair counting the Brits' Monty Python - the Brits have continued to produce high quality televised dramas through the decades).
Of course, there have been exceptions, i.e., exceptional programming of high quality, since the '50s Golden Age - but not anywhere near the level/number of serious, dramatic programs of that decade.

M*A*S*H, for example, was a notable exception with a strong anti-war message, but the message was delivered by quirky characters and slipped in between laughs.

Basically, I simply wish to make the point that the dumbing down of the American viewing audience started before Larry the Cable Guy. I was a television viewer from it's earliest years - my god, I remember a round screen on the first TV I ever say, in 1949! A Raytheon which looked like the window in a clothes dryer.