Pretty much all weapon categories have some elemental ws. Considering some are still used occasionally it was necessary so that they wouldn't have a ridiculous low accuracy.
I'm afraid my ignorance is pretty boundless in this regard until I bother to start playing again, which won't happen anytime soon. But thank you for informing me nevertheless.
I remember in abyssea, magic based weapon skills got super powerful because of the atmas and whatnot, making them really high damage due to lack of resistance and significant boosts to elemental affinity or something of the like.