Depends on the goal, are we trying to make sure their life is worse than the victims to it's own end or are we trying to optimize the outcome for society by preventing future damage and removing as much as we can? If the latter then the inability to negate the effects on the victim alone probably isn't the driving factor on how we create the optimal outcome for society. Especially for crimes where a permanent separation of the criminal from society (e.g. death or imprisonment for the rest of their life) is deemed excessive or too expensive and recidivism can result in more damage than the initial crime if the goal is to expressly ignore integrating them back into society.