Thread is a somewhat failed premise. XIV already attracted younger kids earlier in its life cycle. Who the younger kids are now has changed though. FFXIV 2.0 and beyond has never tried to appeal to older gamers. It recycles a lot of older FFs because the designs are all owned and done, which speeds up the content creation.

Beyond this, they've endeavored to make XIV appeal to mainstream audiences, i.e. non-gamers or new gamers. They have largely succeeded. This is why gameplay is secondary to many many people who subscribe to it.