People often interpret the "I don't trust X" statement to be "belief in the opposite", i.e. P(¬A|X_A) = 1. This is obviously stupid since someone you distrust could happily manufacture evidence for ¬A and then you'd conclude P(¬¬A|X_¬A) = 1 so they could make you believe anything, which is obviously not something you want someone you distrust to do to you.
Anyhow, almost everybody knows today that, for example, eating too much sugar is bad for you, but the majority of the population still does it. That's how humans behave. Often times people do something because it's bad, taboo, or dangerous. And not everybody centers their lifestyle around good health; some people are just trying to get through the day. Today we still have doctors who smoke, dentists who drink soda, etc, though those particular vices are less popular than they once were. And let's not forget, while cigarette smoking has been in free fall doctors have been happily handing out prescriptions to smoke marijuana, even though inhaling marijuana smoke is at least as harmful as cigarettes (most people smoke it less frequently, but that's beside the point). Just because something is accepted as normal doesn't mean the harms are being outright denied.
Although generally the US just has bad tobacco habits. 'European' style smoking of a cigarette with coffee a couple times a week likely will kill you slower than whatever was going to get you like cooking and eating smoky grilled meats.