I agree that all non-smokers have a right to go out, have a meal, have a few drinks, without coming home stinking of other people's smoke. Absolutely. I also think that smokers have a right to go out, have a meal, have a few drinks, and smoke if they want to. If pub landlords, club owners, restaurant owners, were allowed to make their own decisions, you would find that they are all used at least to a certain extent, and the ones which were not turning over enough would go out of business. Those would not necessarily always be the ones which allowed smoking.
I want choice. I have a friend who has never smoked, doesn't want to, but desperately misses going to a pub, hearing a live band in a heady smokey atmosphere.
A place where I worked (years ago) did some research on air pollution. The air in reception (open to the street), was apparently far dirtier (more polluted) than the air in the smoking room. Partly because they had a really efficient air purifier. But still, the road you walk down is not exactly clean.