What would this possibly solve, though? You're just arbitrarily splitting one role (DPS) in two around a delineation that, unlike the melee distinction, has no actual impact in encounter design... all while increasing queue times by making matchmaking more stringent and forcing people onto what are, for many, duller jobs (Physical Ranged, especially).

You still have the exact same job performance and gameplay issues as before. You're just doubly obliged to take the hit and ignore them (by sub-roles being fully required instead of incentivized via a 1% stat bonus).