Weed is more dangerous than cigarettes in my opinion because it makes you high. The reason people don't realize it is bad for you is because it is illegal so nobody does many studies on it so people say whatever they want about it.
But cigarettes give you a high too... a high is a relaxed status, what does cigarettes make you?... RELAXED!
Actually it's the most studied of all illegal drugs. There are hundreds of studies, most of which are generally positive in nature and can be found with simple googles. For the most classic of studies I would cite the Jamaican, Costa Rican, and Greek studies, foremost amongst them, "Ganja in Jamaica A Medical Anthropological Study of Chronic Marijuana Use by Vera Rubin and Lambros Comitas (1975; Mouton & Co., The Hague, Paris/Anchor Books, NY).", sponsored by the NIMH, (national institutes of mental health here in America). Results found no differences between smokers and non-smokers, other than smokers worked more and a few other things. And rates of cancer were lower amongst those who smoked cannabis and tobacco as opposed to those who just smoked tobacco. Damage of some kind may be done to the airways and cilia lining smoker's lungs, but carcinogenisis has never been proven amongst humans. Certainly it has effects, but is it dangerous? Probably not. The fact that smoked cannabis produces tar does not mean that it's "worse" than tobacco. If it causes cancer it's dangerous, that has never been proven, and studies have certainly been done all throughout the world. It's a tool like all drugs. It does things, some of which can be good. Certainly the medical benefit is undeniable. So I would say that it's certainly good in that way.