If it actually mattered much to you, then wouldn't you do a little research to find someplace more suitable for you? If people don't care enough to even look for another place, then it must not be much of an issue.
Wrong. People have jobs, families, friends, lives. It takes time and effort to research something. Even if you really want a non-smoking bar, and it would affect your health otherwise, sometimes you just don't have the time or energy, or the inclination to make an effort to find one. People aren't always rational. Nor do they have unlimited time or resources.
How that justifies legislating away people's right to go to a bar that allows smoking is still something I can't fathom.
It's called democracy. You vote for representatives to represent your interests in the laws you want passed.
Requiring the labeling of food doesn't remove anyone's rights anymore than requiring that food not contain harmful amounts of poisonous substances.
It removes the right of manufacturers to choose to not pay for labels for their food. You can make anything into a 'right'. Doesn't mean it's not stupid.