Peop;e always seem to compare smoking and drinking. Yes, they are both stimulants (or depressants?). The difference as I see it is the human body was designed to drink fluids and has a liver to remove toxins from the blood(in moderation). However, the body was never designed to inhale smoke and when it does, damage occurs.
The problem with smoking is that it is impossible to keep it solely for the smoker, every one else has to énjoy' the experience. If people want to smoke, then do it in isolation. If people want to drink to excess and become absolute nightmares them do it in a locked room,