Hey, I saw the movie when it first came out in 1975!
Back in those days, the movie was shown in "regular" times. It didn't become a midnight "cult" classic until a few years later.
When I first saw it in the theater, some people (mostly older folks) walked out of the movie, because they didn't understand it and thought it was a freakshow, which it was supposed to be.
My reaction was it was a strange, goofball, campy movie, and that seemed too silly for the mainstream. But there was hardly any such thing as a midnight showing of movies back then.
If you remember the scene in the movie "Fame" (1980), where a bunch of friends go see "Rocky Horror...", by that time, it reached "midnight movie cult" status.
Has anyone seen the sequel, "Shock Treatment" (1981)? I haven't, and I'm not sure if I would want to. And has that movie also been shown during midnight in the theaters?