Any (legal) thing in moderation is fine, as long as it doesn't annoy or disturb the other players. If someone is markedly uncomfortable with all alcohol use, for instance, I'd probably stick to the request to avoid consumption at the game table. For similar reasons, most of us (I'd wager) don't allow smoking at the table - it's perfectly legal, but it's also something that bothers a large number of people.
Anyway, I'm not averse to some mild consumption of alcohol, but I wouldn't anyone getting drunk during the game. As I said above, moderation is key. As long as everyone is acting reasonably, there shouldn't be much problem.