It is unfair to exclude FFXI for inspiration towards FFXIV. While many technical aspects of FFXI are clearly outdated, that doesn't mean that FFXIV can't use other forms of it's successes, like it's approach to story telling in an MMO.
In FFXI, I felt so immersed in that game that I basically called it a second home. It's atmosphere was incredible compared to other MMO's that feel more generic to me (WoW nailed it on atmosphere also.). When I entered a dungeon, I felt that sense of danger and mystery. I felt a rewarded being able to enter Lemuria in CoP for the first time. You had that feeling that you were the central character to the world, you felt like you were the one that had to save it.
Like I said, FFXI is outdated on a technical scale, but it's style sure isn't. Even FFXIV 1.xx succeeded in this in some aspects. It doesn't have to have not out of date gameplay to bring in some inspiration.