I just don't think there is enough traffic for each crew skill to justify that.
And what's that break out to, 18 plus subforums? Because you'd have to split the gathering and mission skills into their own since more than one crafting skill uses them. Otherwise people would never get answers if they had any questions on them.
Maybe after launch it'll be different.
This, unless they made a sub forum for only Gathering, Crafting and Mission Skills