The actual Robert Heinlein novel is very much about “fascism is good.” Bob Heinlein was this kind of weird mix of Ayn Rand libertarian, military-fetishist, pedophilic and incest obsessed futurist who also liked cats but not non-white people. The movie was a parody of the ideas in the novel, but Heinlein took those ideas very seriously and they cropped up time and again in his books. He embraced bisexuality while still thinking that the man-woman relationship was what nature intended. There’s a lot to not like about the guy - like fathers being seduced and bedded by their thirteen year old sexually aggressive but still meek and mild daughters, with said daughters proceeding in their quest with the active help of the mother. And so on.

Anyway, I don’t know how many people that enjoyed the movie knew that it was not only a parody, but one that intentionally and in great detail directly mocked the book it was based on.