To your point, it may not be. But people with addictive personalities can make anything addictive. Example, endorphin ruses are not addicitve however, i cannot get enough of them. Intercourse is not scientifically "addidictive", yet many people are addicited. Aristotle put it best, take everything in moderation. As long as you are not causing any detriment to yourself or others, do what you need to. And although smoking cuases cancer etc, so does breathing our polluted air.