It never ceases to amaze me........waitstaff know when they go for a job in a bar that there will be smoking. If it bothers them, find a restaurant or a non-smoking bar to work at.
And if people are that "sensitive" to cigarette smoke, they do NOT have to go into an establishment to be around it. There are plenty of places for the "sensitive non-smoker" to go and spend recreational dollars. They don't need the whole world!