why smoking should not be banned in public places? don't tell me why they should be banned give me an idea on why they should not be banned!

1. Property Rights

Most fundamentally, the debate about smoking bans should center on private property rights. Whether you should be allowed to smoke in a bar should be determined by the owner of that bar, not by busybody bureaucrats who think they know how to live everyone's lives for them.

2. Second-hand Smoke Isn't as Harmful as Once Thought

In 2013 already there were indications that the commonly accepted narrative on second-hand smoke wasn't entirely accurate. The Journal of the National Cancer Institute (which the below-mentioned Slate article calls "hardly a pro-tobacco publication") published a study which finds no significant relationship between passive smoke and cancer:

"A large prospective cohort study of more than 76,000 women confirmed a strong association between cigarette smoking and lung cancer but found no link between the disease and secondhand smoke."

3. Smoking Bans Don't Make People Healthier

An immensely informative article by Jacob Grier in Slate finally sorted through the questionable "proof" behind the second-hand smoke myth. The bans had largely been implemented because early studies believed there to be a correlation between secondhand smoke and heart disease. Politicians, however, should have waited for more research to be done. In fact, Grier reveals that a 2006 study in the Piedmont region in Italy (published in the European Heart Journal) revealed an 11 percent drop in heart disease, a much smaller drop than the 60 percent that politicians had promised.

After a sweeping ban on smoking inside in England, a 2010 study found a heart attack reduction of only 2 percent. That number is so small that it might not be related to the bans at all. A 2008 study in New Zealand found no correlation whatsoever. The Journal of Policy Analysis and Management published a study in 2010 that also found no significant impact in any age group. Similar US-studies appeared in 2012 and 2014.

4. Smoking Bans Don't Discourage Smoking

Moreover, smoking bans don't actually reduce smoking. Data in France (which implemented its smoking ban in 2008) shows that consumption of tobacco products only correlates with prices.