I've seen the whole range of people with serious addictions to it to the use of it purely as medicine in sparing (and as needed) doses.
I personally have a strong aversion to the smoke entering my lungs part. I like breathing. Smoke hinders that. I used to be a smoker for years (a weird one who resisted enjoying the smoke part), and was bluntly addicted to the chemicals in the cigarettes as well as the nicotine. I did not deny I was addicted, I did not deny I was fat when I was, I tend to be pretty honest about what I'm doing to myself. I was also told by docs I could not have children most of my adult life. When I got pregnant, I was like.. holy cow, this is great - it was sufficient reason to never pick up another cigarette, have a baby and lose 125 lbs. I'm now down to a very normal weight.
Coming through that experience, I gained an interest in the culture of people who use marijuana as a medicine or a past-time having a lot of friends who use it/smoke for all sorts of reasons. Some like it, others find it a necessary evil due to illness, others LOVE it-needit-wantit all the time. It IS curious to me how those who are really into its use pretty much venerate to the point of being some miraculous herb AND deny all its negative traits.
I agree there are many positive medicinal applications in its use, but there are a lot of negative effects as well that most hardcore advocates seem to be in complete denial about... I mean common sense stuff... LIKE the compounding effects of THC's accumulation in fatty tissue, for one and the generation of cysts in the body. Or the long-term effect of heavy usage on the brain's functions (there's a lot of lipid in the brain), or even the way it's smoked - with techniques to "hold in" searing smoke unfiltered smoke in the lungs scarring the tissue by burning off the cilia with the intense heat and layering the tar into the bronchial sacs that comes from the resin.
I tried an experiment in talking to open advocates about these things, like the fact that one unfiltered joint has the equivalent in tar of 16 cigarettes. I've found if the smokers endorse the use, they completely and vehemently deny (no matter what evidence is presented) in a nearly fanatical manner that "Marijuana has no chemicals" or that "It is NOT a chemical substance"....
I mean ground pepper is a chemical substance, everything IS a chemical compound of some kind, it's composed of chemistry... but it's interesting... there is truly NO reasoning with the real marijuanaists. I might as well be discussing creationism with a fundamentalist Christian who BELIEVES the earth is 4,000 years old... And there is nothing you can say, it just comes down to oh well...'light it up - let's get high'
Many people who have prescriptions, don't have cancer, terminal or degenerative illness - they are imo just addicts. There's plenty of Rx addicts too. I think addiction is in the person, not in the drug though. Because some people are not addicts, but use what medicine they have to when they have to. Others 'get hooked'.
In reality, it would be better to have legal MJ than people taking experimental drugs that big pharma doesn't even know the effects of (or care - it's all about profit), and now due to many US deregulations within the FDA, they don't have to report effects that affects less than 6% of test subjects (even if it's death). It would be nice to see some regulation with MJ at least so that if people are using it, it's in a medium that is safer than smoking it. You DO need your lungs for the rest of your life...
Oh and I am a firm believer of decriminalizing all drugs. I am also a firm believer that some drugs just DO NOT need to be manufactured to start with, but if you're making them, decriminalize them. It's hypocritical to make it in mass production, then deny it to feed the prison (racket) industry. A rigged game that feeds addictions and the pockets of the rich. Pretty much, poop or get off the pot yo.