It's socially accepted, and way less stigmatized. Also, marketing by celebrities, and the way it serves a purpose culturally. Those two things are re enforced through commercials, and sponsorships. A lot of that is easy to understand, in terms of marketing and advertising, but what's harder is the role alcohol plays in society. Picture a night club, and everyone drunk, now picture the same scene sober.
How are the men and women behaving? Alcohol is tied to sex and partying via anxiety relief/social inhibition in ways that we are not always aware of. That is one of it's base functions. It's not just having a few drinks, that's not what's fun, it's the permission that gives you.