Spoilers follow; you have been warned.
One review said that the bad guy in this movie sexually abused nearly all of the victims. Out of the 9 women who were already in the house or walked in later, I counted three who were sexually abused. Those being the first one, the lesbian, and the object of her affection. Others were eliminated rather quickly and suddenly. Most of the "torture" was mental, as far as the nurses who were tied up in the upstairs bedroom.
Someone wanted to know why none of them fought back. As I recall, the first victim, whom someone here dubbed "the mature leader", bit the killer's lip and her reward was death by strangulation. The lesbian made a grab for his giant knife (a phallic symbol on the killer's part if ever there was one, especially after he made a point of telling the one nurse that his friend Jimmy was "hung like a horse"), and he quickly grabbed hold of her wrist. Perhaps she could have put up more of a struggle for the knife, but most likely would have ended up the way she did anyway. In any case, I suspect we're to believe that she was more concerned for Jenny than herself. We're also supposed to believe, I think, that the rest of the nurses were so concerned for the safety of the ones he'd led out of the room that they were afraid to make a move. Kind of wishy-washy, but they were all tied up (though one did try to untie another at one point) and one, if I remember correctly, was pretty nearly hogtied.
I also read a review that wondered why he singled out those two particular nurses for his girl-on-girl scene when he couldn't have known that one or both might be lesbians. Watch again. He walked in on their conversation during the ballet where Christine (I think that was her name) was telling Jenny that she didn't want her to be unhappy and then proceeded to tell her she had beautiful lips. Then she reached out to touch Jenny's mouth. Psycho Boy was witness to this exchange. It wouldn't have been a huge leap to assume there was something going on between them, even if Jenny didn't have a clue what was going on.
Of the pile of movies I've seen this compared to, I've seen Taxi Driver, Last House on the Left and I Spit on Your Grave. All I can say about that is this: Taxi Driver has the most pathetic lead character. By that I mean, I found myself feeling bad for him. Last House on the Left didn't leave enough of an impression on me to comment on, though it's been a looong time since I saw it. I Spit on Your Grave was the most violent of these films, as far as I'm concerned. Born for Hell, which I downloaded from public domain bit torrents as Naked Massacre, just had the Speck angle going for it. I felt bad for the victims because of what Cain did to them, but didn't really know them well enough to care too deeply about them. And there's no caring about Cain. He tells that ridiculous story about Jimmy-Boy and his wife, but there's no telling if that's true or the made-up ramblings of a madman.
And that leads back to that giant knife and Jimmy being hung like a horse. Makes me wonder if the writer wanted us to think Cain suffered from feelings of inadequacy as far as his manhood. Then threw in that suggestion that he might be gay. As well as impotent. Or did I imagine or perhaps infer that one? Sheesh, I thought I had it all straight in my head.