Envision a spacecraft from another world landing on Earth for the first time. It stimulates the nervous system, and those who are addicted to it cannot function comfortably without it. It idles the brain and destroys the lungs. Other bodily organs age and deteriorate prematurely. It is our major cause of cancer and emphysema.
Cigarette smoke contaminates everything it touches, even people.
But it does, over and over. Most of the users will not come to their senses until death or ill-health comes knocking. By then it is too late. The poison has done its damage. We are disappointed.