[AlexandrB]

I don't think you can frame some of these arguments as belonging to a fringe minority. I remember watching an episode of "Penn & Teller's Bullshit"[1](2004) where they featured several pro-legalization advocates. These folks said or implied similar things (it's not bad for you, it helps cancer patients). These were not marginal "crazy" voices.

[1] https://en.wikipedia.org/wiki/List_of_Penn_%26_Teller:_Bulls...

[leptons]

"it helps cancer patients" is vastly different than "it cures cancer" which is what OP claimed he heard. And yes, it does help cancer patients as well as anyone else in pain. And the smoke is far less harmful than cigarette smoke, it has no additives at all (when grown in a controlled environment without pesticides). And you don't even need to smoke it, it can be ingested in an edible/pill, making most of the arguments against ingesting marijuana completely bogus.