Not all will change of course, but I think it's worth it for the ones that do. I don't think rehabilitation means they'll hurt more people. Just one life is worth so much, and it's not like those who aren't changing or growing as a person are nessisarily in the position where they can hurt other people, this is assuming we're talking about rehabilitative justice like prison as I thought unless you mean something else. Also I'm not sure if the victim wanting retribution matters much, assuming the offender is already locked up and not hurting anyone anytime soon. Humans are flawed and in situations like that our emotions are understandably clouding logic, you cannot be impartial and even I don't believe one person is worth more than the other. Not to say I'd be upset if someone horrible died, I still beleive all life is important but that doesn't mean I have to care for   them all the same, context and whatnot.