My grandfather started smoking regularly in his early teens (he told me his first one was at age 12), and he lived to be 92. And his death was unrelated to nicotine. One of his doctors told him several years before his death that he HAD to get off cigarettes. He asked the doctor if he could guarantee him living any longer if he did. And when he did die a few years later, his lungs were clean.
So while I recognize that smoking isn't good for people in general, there are always exceptions to every rule. And my grandmother lived with a smoker for sixty years and never had respiratory problems during that period. And neither did my mother or her siblings. Not the optimum lifestyle for continued health, but it's not a guarantee of lung cancer.
All that said, smoking cigarettes or pipes or whatever is a bad habit that no one should maintain. They smell filthy, they make everything in your house stink like them, and you look like a fool doing it. It doesn't carry the air of sophistication like it used to, just the stench of choking.