OK, I think you're maybe missing my point.
I don't post in AH and I tend to avoid it. It being probably the single most high-traffic segment of boards, it's always going to be tricky to catch every single infraction, especially if they go unreported.
However - the charter clearly state what you are not allowed to do. Someone having done it without punishment does not represent the overturning of that rule, it represents an instance in which the rule was not enforced.
Your OP states that the purpose of such a forum would be to encourage "better & safer use of these drugs". But that's clearly contrary to the stated rule about telling anyone how to take drugs. So to what extent can you usefully discuss your own experiences without crossing that line? Anything even remotely approaching a description of how you partake of $SUBSTANCE_X is going to be a description of how to take $SUBSTANCE_X.
So either you'd have an entire forum consisting of little more than "squidgy black, wheeeeeeee
", or you'd have a forum whose very existence (be it public or private) would paint a target on the entire site - because creating a space for discussion of illegal or potentially illegal activity will always attract the attention of the authorities. Just go and chat to the folks who publish 2600 if you don't believe me.