Why punish them if they can't control their actions? If they have a disease then they aren't responsible for their actions. How can you punish them?
How does having a disease = being unable to control it?
This is the crux of the matter. When the medical community views a problem such as addiction using a disease modal, an incorrect assumption is made by many people that disease means "can't stop yourself". That isn't what the disease model means. If I have a disease, there are many things about it I can control and some I cannot.
The point of using the disease model is it results in avenues of investigation that lead to solutions. Using the premise addiction is a personal failure generally results in a cycle of perpetuating the problem.
At the same time, if research into addiction and other sociopathic behaviors does uncover evidence the behavior is not controllable, then isn't it better to know that than to just keep letting people out of jail after a crime, using the false premise they have the ability to control their behavior?
Some sociopathic disease exists which still leaves the person with a brain defect but they do have control over their behavior. Just as someone with rheumatoid arthritis must live with the unpleasant consequences of their disease, a person with a sociopathic disease may suffer severe emotional consequences controlling their disease. It might mean a pedophile must restrict his movements and cannot be around children ever. But without recognition of the disease factors in that pathological condition, we simply expect that person to control themselves or go to jail. I expect them to control themselves or go to jail as well but medical research may give that person better tools with which to control the behavior. And where research discovers how to detect the dangerous pedophile from the responsible one, we will also have the tools to mandate incarceration in a treatment facility.
Same with determining through research rather than through social stigma who can and who cannot control their addiction. If meth addicts suffer brain damage which disables their ability to recover, then they need long term inpatient treatment. Alcoholics very often need antidepressant medication.
The point is, medical research can sort out fact from moral judgment and with that provide better tools to stop sociopathic behavior before crimes are committed rather than merely providing the revolving prison door and a lot of harmed bystanders.