how does the taxpayer benefit from the inexistence of rehabilitation programs?

Taxpayers are clearly wasting money on this guy.

Sounds like he gets out in 10 months, and an incredible amount of money gets spent keeping him there.

Imprisoning someone is also a great harm. That harm should have a cost, so that it is not employed flippantly.

Because that's what a social community would do. But where you probably are, such an approach is falsely labeled as “communism” by MAGA anti-social assholes.