The reason why cannabinoids appear to "cure" so many illnesses is because prior to prohibition they were part of the human food chain. Dairy cows ate feral hemp, which was rich in CBD and passed the CBDs to humans through their milk.
Cannabis ought to be legal. It ought to be researched for its medicinal qualities. But people who sell homemade cures for cancer are dangerous, swindling desperate people into forgoing medical treatment in favor of unproven home remedies. The price, too often, is death.