Allow me to clarify:

Smokers are a minority of the population, but form a majority of bar patrons. The two habits tend to be positively correlated with eachother. Smoking is a social habit (frequently acquired socially, reinforced socially, and the shared experience of smoke breaks tends to encourage social behaviour); bars, similarly, are for when you want to get drunk with other people.

The concern is a private property issue, but the bar owners will naturally do what the market tells them. The fact is, even with smoking decreasing, the solid core of bar patrons continues to be tobacco users.

The people advocating for these laws, on the other hand, almost never go to bars. The smoke isn't affecting them (not two thirds of them, anyhow), and it's basically a political manouever to push people around - demonize smokers as The Other, and you'll win votes.

If there actually were a meaningful cohort of people desirous of non-smoking bars, then you wouldn't need a law - you'd already have them.

And honestly man, banning smoking has seriously impacted the bar scene. You just don't get the same quality of people in them anymore.

Just for clarification, I'm solely talking about bars, not government buildings, airports, or other common areas; someone's attendance at the bar is optional. If you're going to ban smoking there, then you can use the same logic to ban smoking in private homes - because it might harm visitors.