You can smoke all you want as long as it does not impact me. If you never receive taxpayer funded healthcare for your smoking-caused health problems - fine. If your exhaled or ambient smoke does not get into my lungs - fine.
One of the important functions of government is to resolve conflicts between individual rights. Everyone should have the freedom to do stupid things - to give up their freedom to an addiction - to engage in destructive self-gratification or whatever, as long as it does not degrade the quality of life of others. Smoking in public common areas thereby forcing people to smell and breath the unwanted and unhealthy results of your addiction falls within the purview of government regulation. You can't play your music as loud as you want anywhere you want whenever you want - there are laws against that and music does not cause cancer or heart disease.
Ah, but there is a difference between a public common area, like a government building, etc. and a private business which, in the conduct of their business does business with the public. Restaurants and bars are most definitely private businesses, and as such are free to allow or disallow whatever they wish, and should be able to do so without government regulation, especially when the business will be negatively impacted by said government regulation. Impeding the abilty of a legitimate business to conduct their business and make a profit (which is what restaurants and bars are in business to do) is not a legitimate function of government.
This is an area where the market should sort itself out. Restaurants that don't want to cater to smokers are fine, as are bars, but it should be the owner's choice, not a government edict that makes it so. Non-smokers can and will frequent those places, and smokers will frequent places where they are welcome. Expecting and demanding that government favor non-smokers over smokers is wrong. Expecting and demanding that government make all places of business favorable to non-smokers is to marginalize one group of citizens to benefit another. Prohibition didn't work for alcohol and it won't work for tobacco, not because it wasn't implemented properly when it was against alcohol, but because it's a BAD IDEA!