I assume it was for stat modifiers at some point while using marksman/archery. Other than that im sure they used it to lump in and allow rdm to use those raw fish eating knuckles for whatever reason that is. But at the time that wouldnt have been a thing. Could be part of the reason, heck if i know. Other than that maybe they just saw weapons with low number of equipable jobs and said "Hmmmm lets tack a few more onto that, M'kay?"