There's a difference between aesthetic nostalgia and what some of these people are asking for. Aesthetic nostalgia is this being based on this to make it recognizable. It is also the reason our races are variations on the races used in FFXI. The nods to past games are part of this too. This is fine because its relatively easy to insert and plays on nostalgia by making stuff recognizable to a degree.
It's another thing to lift something from a console RPG design and try to cram it into an MMORPG. It's a matter of mechanics, and mechanics from one genre into another do not make the transition intact because stuff has to change for it to fit. Sometimes certain mechanics do not make it at all. Resistances just happens to be one of those things.
Utility, even at the bleeding edge, shapes how the masses perceive a job for good or ill. MNK happens to have the highest melee DPS in the game combined with a debuff that is important overall (would love to say "only in Final Coil" but Dragon Kick has been a favorite for a while now).Utility is heavily overrated nowadays.
I'd have no problem with this. The next logical step would otherwise be to gate stuff through elemental resistances (the way raiding was tuned in vanilla WoW). Though IMO materia as a whole needs to be revamped system-wise (AKA how materia is acquired and applied to gear + what gear can have materia melded).