AA is not a medical treatment for alcoholism. It is not an evidence based practice.
It is a support group that many people have found helpful. I have friends who have been helped by it. I think it is generally a good thing for people.
I also think it is a shame that it is usually the preferred (only, sometimes) option for physicians, courts, and community substance abuse centers. There are evidence based medical practices that are more widespread in other countries (Scandinavia for one) that have had a hard time getting traction here.