Actually, I agree with both sides. If you are still actively smoking pot, then you are biased. If you have smoked in the past and have simply outgrew it, that's a different scenario, because you are knowledgable on the subject, but biased by it's influence at the moment.
On that note, I'd like to disbar !K_A! and nominate myself. Hahaha...
Funnily enough I smoked in the past and now I don't so there.