This one I'm a little wearywary about.
In my opinion this breaks immersion as much as seasonal gear does. A tailor shooting big fireballs at Titan? A fisherman withstanding the wrath of Bahamut? I see it as down right ridiculous.
Then there's the question of class restrictions. Some crafting gear is for that particular crafter class only. It is also a reward for the hard work and resources put into leveling that class. Now you let everyone wear it, the prestige suddenly disappears. Same as gatherer gear.