The general public has a huge amount of misconceptions about alcoholics and alcoholism. I don't think the vast majority of "normies" will ever understand us. They don't think or drink like us, it is just outside of their scope of experience. I have reached the point where I don't expect people to understand me.
His wife may never understand that one drink is too much and a hundred is not enough. But, what does it matter? As long as HE understands himself and knows that he can never take that first drink.
Eventually, when she sees that his sobriety improves his behavior, his mood, their marriage, she will probably develop an appreciation for his sobriety, even if she doesn't understand the nature of alcoholism.