So, I just returned to the game after a LOOOOOONG stint away, so perhaps I'm overlooking some sort of important detail. However, it seems to me that Accessories should maybe be tied to your character, as opposed to a specific item. That way, you can freely customize your character, without worrying about accidentally "losing" a rare item somehow.
Specifically, I have the Tails' Tails item, and I'm contantly worried I'm either going accidentally vendor it or something, or even "waste" it by putting it on an item that I don't intend to wear indefinitely. In fact, I'm extremely inexperienced in terms of the game itself, which contributes to my worry. If I could simply "unlock" the Tails' Tails accessory, though, without worrying about whatever items I replace, that would be fantastic!!!
Convenient & Money Sink are not mutually exclusive for OOO.
As nice as it would be to freely move accessories around, even if accessories are bound, there would be a loss of market, because suddenly people don't have to buy more than one "wolver tail" to stick on several different items. And then OOO won't host promo item sales anymore because people don't have to buy more than one. And as long as people need to buy more permanently broken accessories, that'll make OOO happy.
Recently they release accessory unbinding tickets which is sort of nice, but still the prices are sharp and high. You'd have to be unbinding Solstice Crowns, Auras, or Prismatic accessories to sell or reuse to even consider using that feature. In any other case it's much cheaper to just buy new accessories.
It would be nice and convenient if it was the way you said it, but economically speaking it's probably not in their best interest.
I hope that clears things up. : >