Eh, lets be honest now. I do know a few people who need to have weed. When you are smoking 4 bowls a day or more for several years you can't just simply stop smoking. You are dependent on it and a restless mind sucks for them. It is a very extreme smoker, but they do exist and no harm is done in at least recognizing that there are some people out there that need weed to make it through the day.
Yeah, some people just have addictive personalities. My brother in law is unwilling or unable to stop smoking, claims he tried/trying.