We could convince them by means of civil disobedience. We could go on the main Bitcoin discussion board with very tiny btc giveaways and each of us would start linking our address cluttering the page with giveaways bumps. We would obviously get moved to the correct boards (whichever those are, Bitcoin Markets maybe) and then we continue to bump and post our btc giveaways there.

If we could keep it up for even 24hrs giving out 0.0000001 for each address (giveaway amount not important) then we would get the attention of several board members and moderators. Eventually we'll get asked "why are we doing this?" and we should have a pre-planned message similar to:

Dear [board room] Moderator,

Our Altcoin board is currently being bombarded with giveaways such as these but on a scale much larger than what we've committed. We understand that opening up child boards for individual coins is prohibited however not allowing any child boards is nonsensical in our opinion. Altcoin board is debatably the largest board in the "others" section and the 4th largest board within the entire site. We could easily alleviate our problem with a child board for giveaways. Our proposition is to create three child boards for Giveaways, Mandatory Updates, and [ANN] for new coins, as these are the largest three repetitive topics made on our board. This will allow for honest content to surface amongst the clutter. Now that our problem has been brought to your attention, we will stop our interruption of your board.

Sincerely,
Altcoin Board members

I have no promise for this plan and we should ask our Board's moderator first, but this will at least send a message.