Since forever. There is only one poetry thread, and that's the one you linked to - "Bad "Buk-Inspired" Poetry (when you were drunk)" - which is where the first post in this thread went to live.
Letting people post their own poetry is not a floodgate I want to open. There are, oh, I don't know, four hundred million other sites that anyone can post poetry to, so I figure that's enough.
Your hand signed forum policy document is in the mail. Don't try to sell it on eBay.