I agree, and I don't like that attitude either. However, the big question is does it send some people "mad" or were they "mad" in the first place. I reality I think it's probably more likely that it can trigger some conditions that would otherwise have remained dormant. Which makes it's status as a "safe" drug a little bit questionable.You're right it's a complex issue.
I don't like the attitude which says: someone once went mad after smoking a joint, therefore it should be banned.
Mad people shouldn't smoke it - that's all...
Have a bit of crack instead, problem solved.