This line has been reliably trotted out every few years since the 1990s at least: But experts say today’s high-THC cannabis products — vastly different than the joints smoked decades ago — are poisoning some heavy users, including teenagers. The issue is that people adjust their consumption accordingly, just as with alcohol - drinking one liter of beer, everyone knows, is not the same as drinking one liter of vodka.…
I also think that the weed culture is hostile against suggestions of problems. Almost every time I have spoken about possible dangers of weed, even when presenting peer reviewed articles or meta analysis, I have been angrily shouted down. Unfortunately weed users have been prosecuted for so long that they take a dogmatic view about its benefits.