No they don't actually Johnny. Just ask Ian Jack Dunlop, a recidivist sex offender, who was given life sentences plus for a series of horrible assaults on young boys in 1975. The judge deliberately sentenced him with the intention that he would not re-emerge from prison until he was an old man.
I remember Ian's case well, because I knew Ian. He was a likeable, polite and interesting man in addition to being a good guitarist and pianist. He was also a paedophile, who committed a series of terrible offences. I abhor the offences as much as you do. Indeed, I wrote earlier, that if I were in the position to prevent one against my child or yours, the assailant might well suffer serious injury.
However, we do need to distiguish between our abhorrence of the crime and of the offender. Of course my sympathies lie primarily with the victims. They must be the first to receive protection. Most child molesters are victims themselves though. It is easy to say, "They are not normal people". Indeed, they are not. They have usually suffered abuse in the family, sometimes in state institutions and some have suffered abuse in some of the nastier boarding schools, which were very much a common part of our culture in the last century. Given proper support and help, they do not necessarily become offenders. That is what the excellent linked article was about a couple of posts previously.
There is a tenet, which is supposed to be the basis of the philosophy of the Japanese prison service, "Love the criminal: Hate the crime". A vengeful and vindictive justice system is unlikely to change anyone for the better. Why waste money on a system, which sends people out worse than when they went into it?