Burgess uses his stylistic choices to provide a safe "distance" between the disturbing content of the novel and the possibility of influencing his readers. While most novels of this sort are set up as educational polemics, with morals and themes, Smack instead presents problems and mistakes of youth directly from their perspective, with only the opinion of the characters themselves shown. Because of this, the reader never feels as if the events are being specifically presented in a negative light; it is up to the reader to make that distinction.
I'm here, let's face it, because I'm too scared to go inside. I know people who've done time... I keep thinking about the screws and how hard everyone is and I couldn't cope with it...
Funny thing, it wasn't like that when I got busted. I was sitting in the cell thinking, Thank God that's over. It was out of my hands, see? ... No more decisions, no more failures, no more promises and lies. No more heroin. I'd lose everything... I was thinking, What a relief, I don't have a life any more.
(Burgess, Smack, Google Books)
In the above excerpt, Tar is thinking about his choices and how he reacts first to arrest and then to being institutionalized. It is clear that he still thinks of himself somewhat from the perspective of a child; he is waiting for someone else to take control, to make the hard decisions for him. Instead, he finds that he is entirely in control, even when he feels otherwise; the decision to quit heroin is his and his alone. This allows the reader to see from his perspective how hard his life is -- of his own free will. Because of this, and because there is no outside voice providing objective opinion or disapproval, the reader is able to view the events without bias, and thus as a personal reactionary learning experience, rather than a deliberate moral lesson.