Only 60% of Americans drink? I routinely get astonished looks when I tell people that I've never in my life even tried a drop of alcohol. It seems like way more than 60% have had alcohol.
I would never say that I don't drink. So I wouldn't be part of the (in the case you refer to) 40%. But I almost never drink, and never very much anymore. Some years I've had maybe a couple of beers. I will take a little glass of wine a few times a year, at dinners. But I never feel the need to open a beer or drink wine at home. Had to dump most of my wine collection a while ago, the bottles were so old that when I checked, most of them had become vinegar. But if people ask if I don't drink alcohol I would never say "I don't". Because I do. I just don't have a wish to, most of the time.
When someone says that they drink, they usually either mean that they drink regularly or that they will drink again in the future. There are plenty of people who have consumed alcohol who never found much of a use for the stuff.