Like with so many other things, they backed themselves in a corner with their insistence that this game look as little like its predecessor(s) as possible. In XI (and indeed, every other FF game since it was created) offensive magic users had access to offensive spells of all the elements. Depending on the job, they'd have differing levels of those - for example only Black Mages had access to ancient spells - but they could all use them. So the situation where Ifrit is fire-based, you might not hit as hard if you are a Red Mage, but you could still hit. And you weren't there because you hit hard anyway, you were there because you had versatility and utility.

But that would require a complete redesign of the system and while I personally think it needs it (base classes that literally are unusable and pointless, subjobs need to come back instead of "role actions" etc), I don't think we'll ever see it. This developer team thinks we're literally too dumb to understand the difference between fire and firaga, no way they think we're going to understand the elemental wheel.

It's times like this that I miss the XI team. Those guys may have been pricks about a lot of things and leaned on Ps2 limitations a little too hard sometimes, but they always cared about the product and they didn't treat us like we were complete idiots.