These are people who don’t think too deeply because they distrust reason. They are often the same people who wage war on dirt and litter and if prompted will confess to a whole range of other ritual punishments designed to make the world a safer and a better place. Castration for sex offences, including homosexuality would be somewhere close to the top of the list.
These are people who want the world to be simple, they want it to be pure; they hark back to a mythical time (before the war? The middle-ages?) when the world was free of criminality. When there was no pornography and good girls (most girls) saved it for their wedding night.
The people who advocate a return to capital punishment are, essentially, the inhabitants of an animated Eden, lifted complete from Disney World. Everything that is in the universe is meant to live in harmony and peace. All of the creatures who live there know the words to the chorus. From time to time a Crocodile comes along or a pirate with a wooden leg and blood dripping from his sword. But it’s not a real problem; the dragon is killed and everyone can go back to singing and dancing.