It really does seem to me that anyone who really accepted that "non-smokers' rights are just as important as theirs" and recognised that their smoking caused real discomfort to others, would make a point of going outside of any shared room in order to smoke, even where there was no legal requirement to do so.

Sitting just behind the line across a room between smoking and non-smoking areas just wouldn't be good enough, given the way smoke ignores boundaries like that.

Good manners and consideration for others should have meant there would have been no demand for a law and no need for one.