Simple math. If one person in ten spends 10% of their income on tobacco, then the average person spends 1% of their income on tobacco.

More families than you think spend $0/yr on liquor.

I don't have a 'family', but I only spend maybe $250/yr on alcohol, and my girlfriend doesn't spend any, and we are in our mid-20s.

It's not for any moral reasons. I only drink beer that I think is tasty, and then pretty much only with meals at restaurants. She just really doesn't like the taste of alcohol.