I think there's a difference between work place hazards that can be easily prevented and work hazards that just come along with the job. For instance, being a soldier in the army can be dangerous, yet you don't see any countries outlawing militaries, do you? Many businesses cater to a smoking environment and many people enjoy a smoking environment. That being said, it should be understood that smoking is a hazard (if it even is) that naturally comes along with certain jobs.

Warehouses don't want asbestos- the asbestos doesn't serve any purpose. It's just toxic waste. Smoking is different. It's something that some people enjoy. Outlawing it means that those people who enjoy it can't do it. If you don't like the smoke in a restaurant- don't go in/work there. You don't have a right to go in to/work at a privately owned business- you can go in/work at only if the owner allows you to. These people want to smoke in a building that is owned by someone who wants them to smoke in their building and the owner may or may not also want you in their building, so you saying that they can't smoke there is just wrong. It's just none of anyone's business except for the owner's.