It is underrated, but we're talking soundtracks, and for me, a piece needs to memorable in both being something I can hum along with and something that evokes the experience of the game. This usually works well in games like IV and VII because the music is used to add emotional depth to a scene. When you hear it, it should take you back to that opera scene or that fallen city in the rain. XII's OST is great for being background noise but doesn't lend itself well to infusing itself to the scenes itself. There's a disconnect. Same with FFXIII where barring the battle themes which all sound suspiciously similar, it's really hard to remember another track from it that can stand on equal ground to The Lunarians, Home Sweet Home, Terra's Theme and Those Chosen by the Planet.

On their own merits as a piece of music, they are great, but they are meant to serve as a part of a collective whole. Sadly, this role has been diminished over time with the series as the music is no longer really left up to enhancing a moment but instead being a cohesive but largely behind the scenes element of the game, that simply serves to compliment rather than take center stage and enhance the scenes. Ashe's Theme is a great them that really tells well for her character but for the life of me I could not tell you where it even played in the game. Worse is the fact that in games like FFX, XII, and XIII some of their best tracks are one-scene wonders that are all too short. My problem is that I prefer my soundtracks to stand out, not stay in the background, and sadly the majority of both their works are designed to stay in the background. I love FFXII's soundtrack but I would be lying if I didn't say that I felt FFTactics and Vagrant Story were better OSTs. Hell SMT1 and 2 (both by Sakimoto) have far more enduring themes that are still being remixed by newer composers at Atlus instead of changed.