Some ideas that affect why we can't quit:
1.Some actually like the taste after a cup of coffee or a cocktail
2. Some have Addictive personalities
3.The chemical in the cigarette causes the person to go through withdrawal, thus requiring a smoke, per say
4.Habits are hard to break
5. The chemical helps those who require pacifying to satisfy that need
6. It is clearly a choice. Everyone knows it causes cancer, more health issues.
Hence anyone who smokes should pay a much higher premium for health insurance. I do not see the need to support a choice of cancer of death.