Because it is simple. You do not have the right to tell other people how to live their life. If secondhand smoke is not a valid thing (which multiple reputable sources are showing is true), then you have no reason to scorn smokers besides personal bias based off lies. It also means you definitely should not be voting on or supporting bans on smoking unless you do not believe in personal autonomy, in which case you live in the wrong country dude.
If you want to get into actual ""deadly"" facts about smoking, according to
this article which states:
Cigarettes cause about 1 lung cancer death per 3 or 4 million smoked, which if I were to take my smoking rate of 8/day, would take me 1027 years of smoking to complete 3 million cigs. There are also facts like:
Lung cancer today is primarily caused by the inhalation of smoke from cigarettes, which is also why the disease was quite rare prior to the 20th century. Which focus primarily on cigarettes, and not things like air pollution from industrialization and cars. It might speak volumes to know that
lung cancer rates are actually INCREASING even though smoking has dramatically DECREASED over the past 60 years. To quote the article directly for you;
Again, none of these facts show that smoking is good for you. What they do show is that there is more to the story than just smoking. If we allow the anti-smoking hate groups to keep pushing propaganda research at us, we lose sight of actual issues causing actual diseases in actual people by things they have not chosen to do. It's become taboo to even think that secondhand smoke isn't a big deal even though multiple studies have shown it only matters in extreme fringe cases. It's an argument against pure logic, and it's ridiculous.
The argument you are making against smoking as telling someone how much soda they are allowed to drink a day or telling them they HAVE to exercise every day, or else we will fine and jail you. You are forcing personal beliefs of your own onto how another lives there life. This is discrimination 101 sir, please get the context right. Don't ask me to prove an argument that I am not making nor agree with, there are "safer" though I wouldn't say better ways to get nicotine (smoking has a faster delivery system of the drug and safer is in quotations for a reason). Unless you can show me long term studies done on the effects of wearing nicotine patches or vaping over a lifetime? Keep in mind that you don't see a increase in cancer until 30-50 years of smoking. At least according to the internet (and matching with my memory of vaping)
The Chinese firm Hon Lik made the first modern e-cig in the mid-2000s so if you have a long term study on the safety of vaping throughout a lifetime, I would be very interested to see proof of time travel.