If you show me a person that is immune to cigarette smoke and scientifically prove how this immunity works on a biomolecular level, I will withdraw my statement.
As much as I would love to produce a circumstantial proof of evolution of our lungs, I do not do research in that field. But there is plenty of research on virus immunity and cancer that supports what I said.
People simply are not that different. One big difference between groups of people is lactose intolerance. Some people have it, others don’t. Therefore, drinking milk is neither considered a healthy nor an unhealthy lifestyle, it highly depends on the individual. Smoking does not. It affects everyone, some more than others, sure, but noone is immune.