This game is a hell of a lot of awesome if you're not a complete jerk about the storyline. There is actually a huge backstory to the game, and if you unlock the stuff in the bestiary and explore around you can find it.
I think this was actually a huge step forward for FF's; imo the arguement that optional content is not worth it is counter-intuitive; its optional so quit whining about it. It's not like the monster arena was incredibly significant to the main plot, or hunting down every blue magic in FF6 (or 7 and so on).
It might have been disappointing or whatever story-wise, but actual content-wise it's bar none the most varied.
XI Wiki

