Why? That's just an assertion. You've not given any reason for it. I can counter-asset that "an eye for an eye would leave the whole world blind". Great, we've both proved we can recite vague platitudes, but the argument hasn't progressed.
I don't know, I thought my "The punishment should fit the crime" was a perfectly succinct response to your post and even allows for someone with diminished mental capacity (where applicable and probably not in this specific case, might significantly alter the punishment). Of course victims shouldn't directly determine the punishment for a crime, that should be left up to society as a whole.
Doesn't work like that. It is relatively rare for people to sit down and think through the rational consequences of their crimes like that. Most crimes, particularly death row ones like murder, are the products of say, heated in-the-moment disputes that spill out of hand, or people who've more or less discounted their futures anyway, or people who don't have the mental capacity to weigh these things up. Changing the sentence from 21 years to execution doesn't have any impact on anyone who falls into those categories - if you're mentally disabled, you don't have the capacity to make that kind of rationalization. Empirically, this is a fairly-well proven point; basically every meta-study I know agrees that the death penalty has no significant effect on crime rates.
It doesn't require one to "sit down and think through" it, as just about everyone knows, before commiting a crime, that say murdering someone will automatically warrant the death penalty (in certain states), so for a sane person, not high on drugs or experiencing serious withdrawal symptoms, who hasn't previously committed a serious offence, if they absolutely don't have to kill someone, why wouldn't
some consciously choose not to, to avoid the automatic death penalty? To say it has a negligible deterrent effect, goes against human nature of risk versus reward, with keeping ones life, being the rather large reward.
