I’m a non smoker. Never have taken a puff. Never will. Consider that a disclaimer of sorts.
As an Illinois resident, I’ve seen the results of government requiring business establishments to be smoke free. There are places I’m more inclined to go now. I suspect that my spending in a couple restaurants is up since the ban went into effect a few years back.
A valid argument against the ban in Illinois and elsewhere was that smokers would be less inclined to stay away. Cigarette smoke and poor ventilation did keep me from going to certain establishments.  Some businesses will be making up the loss with new, or more frequent customers.
Several years ago, Ireland went smoke free. I spent a couple weeks there before the ban went into effect. I heard the same worries from publicans (that’s what they call bar pub owner or operators..) By the next trip in 2006, the ban was in effect and the Irish adapted.  The pub atmosphere tended to win out over the desire to smoke.
I like the result. But to me, the decision is best left in the hands of the business owner.