Yes, the criminal justice system should focus on rehabilitating criminals. The present system of imprisonment as punishment is notoriously ineffective in deterring crime. If criminals were rehabilitated instead of punished, they could hope to reintegrate into society in a positive way, rather than fester in prisons that have become breeding grounds of more crime. It would also save taxpayers countless millions of dollars if criminals were rehabilitated and released instead of remaining useless in cells.
Rehabilitation should absolutely be a focus of both prisons and the court systems. Repeat offenders tend to prefer institutionalization because of the safety, the roof over their heads, free food and medical care. This eats up tax dollars. The country as a whole is better off if we rehab offenders to the point of being productive members of the tax base.
Recidivism rates are high when it comes to people released from prison in the United States. Multiple research studies reveal that the recidivism rate decreases when the focus of incarceration shifts from being merely punitive to becoming one that focuses on rehabilitation. While rehabilitation programs are more costly than the status quo, in the end money is saved because the crime rate reduces and fewer people return to prison.
When the American criminal justice system was devised, those who had come to America seeking refuge from countries where they could be arrested, held indeterminately without charges brought against, punished or even killed on the whim of frivolous and sometimes tyrannical leaders wanted to insure that the American system did not follow suit. They had an idea that everyone could be rehabilitated, and designed a criminal justice system based on that ideal. Unfortunately, over time, it has become more about punishment. But that was not the original intent.
Keeping people in prison for long periods of time is expensive and research has shown that it is counter-productive. The US spends a ton of money on keeping people in jail and it doesn't have low crime rates to boast about so, again, yes, we should rethink how we handle criminal justice.