That's the crux of the situation, though; on hard liquor, the slippery road to becoming a non-functional alcoholic is much steeper.

There also might be a gender difference. In my experience, men who drink wine, mostly drink with friends and self-limit. The sort of men who are prone to alcoholism won't be satisfied by mere wine and will proceed to hard drinks quick. On the other hand, women often drink wine alone and might develop a daily habit that degrades into full-blown alcoholism even without resorting to hard drinks.

FYI, I barely drink at all and I dislike sloshed people (incl. myself when I rarely get intoxicated; it is an unpleasant state to be in). But even hell has layers.