Yeah but that would require them to pay attention to the story and reflect on it so they understand the consequences. For a lot of people, they never make those connections, and anything on the screen being depicted is also being encouraged and glorified in their minds.
The book maybe but the movie definitely glorifies the violence without direct context for why it’s wrong. At least to a degree that can be easily understood by the target audience of teenage boys.
So, the director hid a swastika in one of the shadows to indicate that he thought the society was evil, among a ton of other things. He talked about it in the director's commentary. But yeah, it's actually super easy to miss unless you know it's actually a warning (which, like you said, the teenage boys it's marketed to wouldn't understand)... Which is kind of the problem with a lot of media, like the entire genre of cyberpunk.