Money and emotional trauma are not equivalent. When a thief is forced to give back the money they stole, the victim tangibly benefits. Torturing murderers doesn't tangibly benefit the victim's surviving family members, because emotion isn't transferable capital.
Thus, our goal should be the lowest possible crime rate, and I'm not sure punishment for vengeance's sake is ultimately compatible with that goal.
> When a thief is forced to give back the money they stole, the victim tangibly benefits [... while] emotion isn't transferable capital
I propose that you would feel differently if someone had emotionally assaulted you or your loved ones via rape or violence. Perhaps this is a difference in personal ethics, but I despise such assaults more than property damage; at the very least I hope we can agree that such crimes deserve to be redressed.
Thus, our goal should be the lowest possible crime rate, and I'm not sure punishment for vengeance's sake is ultimately compatible with that goal.