I can't remember where I read that, but someone had made an interesting observation that stayed with me, and your comment makes me think of it (perhaps you're referring to the same article?)

What if instead of slowly dying of cancer, smoking had a tiny tiny chance of making you die by exploding your face? Exact same probability of dying, just very violent and graphic.

Chances are barely anyone would smoke. Yet, same death rate.

To answer your point, I think smoking is worse than making your head explode, it has a much greater societal cost in healthcare than if you were to die there and then, and creates much more suffering.