PBS might have surprised in the '70s because they were far more liberal with their programming back then than they are today. But then back then there weren't all the supposed "moral majority" protest groups that cropped up in the '90s and still exist to this day, and if even the slightest bit of PBS programming offends them, they're soon to be running to the FCC complaining that their tax dollars are being used to fund smut or whatever foolishness they want to complain about!
For example, I remember back in the '70s I was quite surprised that PBS ran Glenda Jackson's
Elizabeth R uncut because it contained quite a bit of nudity. And who can forget the production of
Caligula. Both shows would require that PBS heavily edit them today.
Even some of the '80s P. D. James adaptations for
Mystery would probably require editing.
Sad, really...