It isn't hate. There is an equally rational side that suggest that painful death as a consequence/punishment of violent crime DOES have a deterrent effect, even if minor.
If it's pure pragmatism driving the decision, then the question becomes whether the decreased crime from the deterrant effect of painful death as a punishment is greater or less than the _increased_ crime from the same. It's fairly obvious that there will be at least some people who will prevent themselves from committing a crime when the punishment for that crime is horrible. The thing is, there will be plenty of people who will still commit crimes anyway. Some of those criminials will inevitably be witnessed, or will have someone try to stop/capture them. With the prospect of painful death as a punishment, even a small child who happens to glimpse the face of a criminal becomes a deadly enemy who needs to be dealt with. So, inevitably, as punishments get harsher, the people who will committ crimes anyway will committ additional crimes in order to cover up the original crimes. So, once again, we have to ask whether the reduction in crime from one angle is greater or less than the increase in crime from another.
Another angle to consider is respect for law and order. Some people equate fear and respect. Some people respect others for their displays of dominance, strength and brutality. Many of the supposed fans of law and order seem to fetishize inhumanity towards ciminal undesirables. Just look at, for example, Sheriff Joe Arpaio of Maricopa county. As far as I can tell, he's corrupt, not actually particularly effective, and costs his constituency far more than he's worth. But many people love him and keep voting him in because he's brutal to the people kept in his jail (which, as a jail, houses a fair number of people who have not yet been convicted). The problem is, there are plenty of people who, rather than being excited by such things, are disgusted by them instead. They lose respect for the "law" because it appears to be just case after case after case of might making right, with actual law and order being ignored by people who think that they _are_ the law. The damage to society that sort of thing can cause shouldn't be discounted.