If somebody is stupid enough to let a pedo out out of jail, I don't want him to have access to the same tools he used previously to interact with these children. This is no different than when a drunk driver loses their drivers license.
I am completely willing to accept that some people might be rehabilitated in prison, but I am not willing to take the chance with pedophilia. Certain crimes I would be more lenient with, but one of the most heinous crimes is not something I feel comfortable releasing.
I would much rather pay to keep a pedo in jail then risk any child is hurt.