At least if that was the case, I might agree, but until then as long as they are locked away I don't see the difference. It's not like they are going to have a fun time in the slammer, come on.
It costs a fortune to keep them in there as they need to be protected from the general population who would (here in Oz anyway) do everything possible to make their lives more of a living hell than their victims had suffered before arranging an "accident", even the worst criminals here have no tolerance for paedophiles and that's probably because quite a few of them are victims themselves.