Primarily because the program works, and all it is doing is changing what you believe about yourself and smoking.

If the program is only changing your beliefs about smoking, and the result is that you - while smoking all you want in the process - gradually stop smoking without even trying and then over time become a permanent non-smoker, then it stands to reason that it isn't nicotine that's really the problem; it is, instead, what the program is changing: your beliefs about smoking, and being a smoker.

Couple that with the fact that after he nicotine leaves your body (takes about 14 days from the last dose), there's nothing there to actually cause an addiction response anymore (except your accepted beliefs about what you should experience), and the fact that hypnosis can achieve the results it can, and you have your answer.

The problem with quitting smoking isn't nicotine, it's what you believe about smoking, and what you believe about your self identity as a smoker.