"The assumption that all smokers are selfish and wish to force their habit on other people etc., is a downright infantile attitude and does not merit any further attention."

Well, should we assume instead that all smokers are helpless and can't help forcing their habit on other people? Let's see. If you light a fag in the presence of other people you either wish to force it, don't give a monkeys about forcing it, or you can't help forcing it.   Which is it to be? Choose the one which is, in your opinion, the least infantile option and I'll adopt it from now on.