IX was underrated mostly because of it's graphics. If people could get past it, and actually see the story for what it is; it becomes quickly prevalent that IX has the deepest story of the PS1 generation.

IX does have the "journey myth" in it though. It's just not as obvious or as centralized. IX doesn't have a main character, but each character walks their own personal journey as they show the player what defines them. It's shown the strongest in Zidane, Garnet, Vivi, and Steiner though. IX's theme is "The Meaning of Life", in context of this theme, each character symbolizes one of the paths that people choose as what is most important to them.

Zidane finds meaning in helping people, Garnet finds meaning in family, Steiner in duty, Freya in love, Eiko in friendship, Amarant in freedom, and Quina in selfishness. Vivi represents those who are still looking for their own purpose and ultimately finds it in helping to lead the other black mages. Of all the FF's, I feel this one expresses it's theme the best.

It's a shame more people didn't like it, cause it was very beautiful. Definetly the best of the PS1 generation. I also enjoyed the references to the older games as well as being a more traditional fantasy game... well as "traditional" as the FF series actually gets.