The armoire exists to allow you to save 'special' pieces without taking up your inventory, while also minimizing the server space necessary to store them, thus all potentially unique values being reset. It's not stupid, but actually a creative solution (since for some reason they're unwilling or unable to upgrade the servers).

That said, we really need SOME storage solution for unique drops...I have almost an entire retainer full of JUST body pieces, most of another for other slots, plus three full of mats and random fishing junk since I'm an omni crafter/gatherer...