You expect moral consistency from any body of more than 2 people who aren't family?
The Volstead Act never prohibited drinking - it prohibited the sale, manufacture and transportation of alcohol. That effectively outlawed drinking, but if you had pre-pro stashes, go for it.
Then let's not forget there were religious dispensations (Catholics have to have their sacramental wine after all) and medical dispensations - you could get a prescription for booze as well. (sound familiar?)
Yes, prohibition in this country is silly and wasteful. Now that's not to say there wasn't a point. If you read the history of the tavern culture in pre-prohibition society, it was not in a place where we'd considerable acceptable today. Far more old west and men getting soused every night, gambling fortunes and sleeping with women of ill repute, etc than the clean bright pub life we like to think happened. Could that have changed without prohibtion? Undoubtedly, it already was, but prohibition put the brakes on that culture and ironically opened up a more inclusive culture of illicit drinking.