There are many things that people do for enjoyment that are not good for them. I've never smoked and encourage others not to as well but for many, it's a way to deal with stress, a real killer. I would rather have them smoke cigs that drink liquor or smoke pot. When you look at the damage done by alcohol to themselves and to society it doesn't compare to the damage done by smoking.
It's all about abuse versus moderation. I would argue that the most abused substance in our society is food. Heart disease is the number one killer and so much of that is related to just being fat and eating too much.
What are you going to do? Pass a law? All you can do is just educate people and let them decide. Everyone knows smoking is bad for you. A guy I worked with just had a near-death experience related to decades of smoking. The doctor told him he absolutely has to stop smoking as he's at a stage where it's killing him. He stopped for about two weeks but just the other day I saw him outside puffing away. I looked at him and shook my head. He just shrugged his shoulders and said, "I'm going to die anyway."
He's near 70 years old but looks older. Very skinny and frail looking. I guess he figures he doesn't have much longer on this earth and how much extra years would quitting smoking add. Years, that he doesn't seem to be enjoying now since he has a host of health problems. I guess he might as well do one of the few things he has left to enjoy in life.
