May not necessarily be a thing that only 'alcoholics' do. Or maybe it is.
I think society tends to not look down its nose at those who drink. Alcohol is socially accepted. Because it's socially accepted maybe that contributes; what she is doing, while to excess, is socially ok. What you were doing is much less socially accepted.
Or maybe it's just part of the human condition to minimize what we ourselves are doing versus what someone else is doing. It's gets the attention off my mess and focuses back on you. If I'm busy pointing fingers at you I don't have to pay attention to what I'm doing.