I don't think there is any absence of it so much as a difference in degree when compared with certain other cultures. That's the thing with the melting pot: You can find a little of everything, including people who don't drink.
I think the prevalence of workaholics may have something to do with it too. Drinking on the job is very seriously looked down upon here, but if you can't drink while you're working and you're always working then you're never drinking.
I think this has changed over time, from the three-martini lunch of Mad Men in the 1950s, to (say) two-martinis in the 1970s to perhaps one-martini in the late 1990s. I remember a working for a software company years ago where the "old guy" on that particular group would have two beers when we went out to lunch mid-week. The young guys chose caffeine.
One of the things I like about France (as an Englishman living here) is that it's still normal for people to have a glass or two of wine at lunch. I think it's remained in the culture because most businesses give their staff two hours for lunch and subsidised meal tickets they can use at any participating restaurant (which is pretty much all of them). Who wouldn't have a glass or two in that setup? :)
I think the prevalence of workaholics may have something to do with it too. Drinking on the job is very seriously looked down upon here, but if you can't drink while you're working and you're always working then you're never drinking.