Because how would somebody with no job history, a mental age of a pre-teen, a history of inappropriate violent and sexual behavior, poor money-managment skills, pathological narcissism and a refusal to learn basic responsibility be able to support themselves? The "adulting" milestones that Chris missed should have been learned decades ago, and now he is an incestuous rapist on top of it. It is too late to teach him anything like this, and he will not learn any of it.
To let Chris join society again would be dooming him to be re-incarcerated for some other heinous crime as well as the person he will commit it against.