An interesting revelation was made on CNBC by one of the architects of the New York City e-Cigarette ban. Earlier, a group of retailers pleaded with the council pointing out that this ban had no basis in science. It turns out that the council doesn't really care. Even the previous smoking bans were less about science and protecting people and more about denormalizing smoking.
So it seems it's more important to socially engineer the city to your expectations. Even that means subjecting people to smoking instead of a well documented form of nicotine that is orders of magnitude safer than smoking.