This "blurring" is precisely what makes pro smoking ban people bad people.
They know a bar or restaurant is private property. They know full well. It's just that they are not getting things exactly their way if there is smoke in the air. So, oh, lord above, something must be done. Admittedly, some are merely stupid, but the vast majority of smoking ban people are, by definition, evil. They know what is right and wrong and they choose wrong.