First, it takes life.
Second, it encourages the taking of life and other forms of revenge. Not only is there no evidence that it reduces crime, but it is defended in the same terms that many criminals use to defend their actions.
Third, it is dishonest. If we are going to kill people, we should do so publicly and graphically. Outside of Florida, where the victim’s head sometimes catches on fire in the electric chair, we have made murder look like a tetanus shot. When we hide from ourselves