"Smoking"

As we all know smoking is especially unhealthy for us young people because it produces adverse effect on the blood.But the question there is, why do most of the people do it. Is it really just because of addiction? Some say it is good for our body especially on cold and rainy days. But the disadvantage of smoking is really very BIG because , it can give you cancer in the lungs, which is really bad because it is where breath in oxygen and breath it out. So why don't people just drink some hot soup to warm themselves, why does it have to be smoking???