When I first started coming here I thought there was some type of bias. Now I believe that it is very difficult for a marriage to survive alcoholism, even when recovery has begun in earnest. Not impossible, but difficult. Perhaps if the alcoholic gets sober early enough, the odds are better.
The reality is, marriage take work, even without addiction. There are certainly marriages which not only survive alcoholism but get stronger in recovery. I know one couple who fit this description.