Comedy stylings of PBS?

When I was growing up, I watched “Monty Python’s Flying Circus” and “The Benny Hill Show” – two British comedies – on the local PBS station.

Every night, these comedies would air back-to-back.

Thank goodness. They were such a joy to me, and I’m sure they had an influence on what I found and still find funny today.

It occurs to me:

Why were these unorthodox, norm-smashing, often bawdy, occasionally racy, and sometimes rude comedies on the same station that featured shows like Nova, Sesame Street, The Joy of Painting, and This Old House?