There are professionals out there who believe moderation is possible for some "problem drinkers"--Stanton Peele is one of the leading advocates. I spent four and a half years as a member of "Moderation Management" TRYING (obviously unsuccessfully) to learn to moderate my drinking. In that time, and since (I still interact with MM in the form of a subgroup that has concluded they cannot moderate), I encountered maybe two or three people out of the hundreds and hundreds who participated in this forum who apparently eventually were able to moderate on a consistent, long term basis. I doubt they were alcoholics to begin with, though they were worried about their drinking.
In my experience the VAST majority of people who have gotten to the point where they need help with an alcohol problem cannot successfully moderate--even the occasional "social occasion" (weddings, etc.) feeds the obsession and brings it back to life. You can't turn a pickle back into a cucumber. There is something physiologically different about alcoholics and the way they respond to alcohol.
EVERY alcoholic wants to be a normal drinker. It would make life much simpler. But it just doesn't happen that way.