***to protect the innocence of youth***
Not so! back then the Hays Code was enforced, movies were safe for kids. Some few were for “mature audiences only”.
When Bobby Kennedy was murdered everything changed. Guns, comics, pulp fiction TV “violence”(still safe for children then), Movies all were blamed.
TV shows dumbed down to kiddie shows, pulp fiction removed their lurid covers, movies on TV were butchered to remove every hint of “violence”.
The movie industry said they would police themselves with a joke of a “ratings” system. The Hays Code was DEAD! FILM ‘EM BOYS! Scenes were reshot to add nudity and get a coveted R rating.
Some movies rated R back then now are given a PG rating.
Years ago it was found that the trailers for R rated movies were made to attract the underage crowd. It has NEVER been about protecting kids. It is about getting them into theaters no matter what age.