I have always thought it was a bad idea to ban smoking in pubs, clubs and restaurants - what I'd like is for such places to have to be either 'smoking' or 'non-smoking', and councils involved in licensing them so every area has a balance of smoking and non smoking establishments. If a pub or whatever is the only one within a certain radius, it would have to be non-smoking, but other than in fairly remote and sparsely populated areas, most people would have a choice.
Smokers would have their pubs/cafés/restaurants/clubs etc that smell of smoke, where they can enjoy a fag with their drink/cake/meal/music, and non-smokers like me would have places where I could enjoy all these things without cigarette smoke.
I was brought up by two smokers, and I hate the smell, and the way it makes me feel, but I can still see that there are ways to compromise so everyone is happy - or happier, at least.
I would just say that, unless you completely deny that there are any risks from second hand smoke, the other smells in a pub, whilst sometimes unpleasant, are unlikely to make someone ill - as someone else said, someone standing next to a smoker has no choice but to share their smoke, if they can't move somewhere else, but if I am standing next to someone who is boozing or eating junk food, that won't affect me, and I won't have to move to get away from it. As a non-smoker, I used to hate being in a restaurant that had smoking and non smoking sections, because no matter how good the air circulation was, I still ended up with the smell of cigarette smoke spoiling my meal - and it never seemed fair that I should have to move just so I could enjoy my meal without the fag smoke making me feel sick.