While I agree that rehab should be made more available there is the problem that it all starts at home. If a prisoner doesn't want to be rehabilitated, nothing is going to work. Then there's the idea of who we're interested in rehabbing, sexual offenses? Right out, nobody cares, if somebody is a sexual offenders(Doesn't even have to be rapist or molester) they're getting out and pretty much doomed. We don't really like violent offenders either, and have little interest in fixing them, some for drug offenses, but the money isn't really there. Then once they get out there's the problem of habitual strain. When somebody has that felony conviction they're estranged from society, family and friends, they have the problem of finding work and of the things that drove them to crime in the first place.
Rehabilitation is hard and we don't have a great way to do it. So we'd rather stick with what works(at least to the extent it works).