After all, rapists are not castrated against their will, so why should it make the news?
Actually some rapists and child molesters are tormented by the knowledge of their crimes, and by the ugly compulsions they feel. For these, castration is a relief. In addition, it allows the possibility of freedom without the danger of offending again.
I am not suggesting that normal sexual desire is dangerous or evil. Rather that, for some men, there is an abnormality in their sexual urges. The reasons for this can be disputed. Probably it is not physiological in itself. But the fact is that some few men are driven by destructive sexual desires, and castration gets rid of the desire. If they have any conscience at all this will be a relief.
I heard, under confidential circumstances, about one such man's experience. He was a teacher and a child molester. He was so tormented by what he did, that he decided to castrate himself. He didn't seek out a doctor probably because he was afraid. He castrated himself and almost bled to death, until he called 911. He went back to work as a teacher (he hadn't been caught) and no longer had the desire to molest children. He felt much better!
But hen he started feeling depressed and somehow got the courage to seek help. The psychiatrist (idiot) thought his depression was related to a deficiency of testosterone (due to his castration) and prescribed testosterone replacement therapy. The teacher described the result as "a living Hell." His horrible lusts returned. Naturally he stopped the therapy. The fact is, a person with anything like normal sensibilities will be depressed at the memory of committing such crimes. He would just have to work through it.
So, I agree that there is merit to the idea of castrating rapists, particularly if they want it done. It is a difficult subject. As a decent human being who is neither a rapist nor a rape victim, I am sensitive to the idea of castrating somebody against his will. Nevertheless, I can see tha castration can be a benefit both to society and to the rapist himself.