Enough proof for you doesn't equate to scientific proof or enough proof for several million others.
I don't deny that nicotine CAN be an addictive substance. Some are able to resist addiction better than others. (scientific fact)
So, what's addictive for one person may not be for another. To lump all smokers into the lump of "addicted" is not at all correct and condensending as all get out.
And like another poster said, until the surgeon general changed the term "addictive/addicted/addict" ANY smoker was not considered "addicted". Since that time, chocolate is also an "addictive" substance.
Alcohol is addictive. Prescription drug use is addictive. Coke and Pepsi has addictive qualities. How about we smoke because we just enjoy it? What's wrong with that. It's legal.
Obesity far outweighs health care and disease today in the United States then smoking! The government has already started on FAT people! It never ends.