What makes you think that crafters and gatherers who play this game for the in-game economy are such a small minority? There are huge free companies dedicated just to crafting. Crafting is an integral part of this game and the in-game economy is a big draw for many players. It's also what keeps a lot of players subscribing and active in the game.
Maybe you haven't played a lot of MMOs? How can you not understand how essential the game economy is to this type of game? It kinda boggles my mind.
Also, there's no magic way that they can definitively "solve the problem" forever. No matter what they do, RMTers and hackers will still try to find ways around the system. So how would they know when to unlock the boards?
And as soon as they did unlock the boards, RMTers and botters would rush to find new ways to mess with things. Your "solution" to lock the boards until somehow the problem is "solved" doesn't actually help the situation in any way.