I think the point for Ellenpoly, and certainly for me, is that being exposed to a room full of tobacco smoke for more than a few minutes at a stretch actually does make us physically ill. I limit the amount of time I spend in places where people smoke for the same reason. It makes me physically sick, not just during the time I'm there, but for a few days afterwards as well. We avoid enclosed places where people smoke because we have to in order to be able to function and not feel utterly miserable all the time, rather than because we want to. We might spend a lot more time in such places if they were smoke free.