I tend to agree with Dee in that, according to studies "everything" gives you cancer or is harmful these days.
Would drinking less than 20 units a week be worse than eating a lot of fat in your diet, for example? Or not taking enough exercise, or living next to a nuclear power station?
Where I do agree that alcohol is very dangerous even for non-alcoholics is things like accidents, drunk driving, people binging on a weekend and fighting and commiting crime, etc.