The combat system is indeed interesting... but the story is fanfic-tier garbo. And the fact that right off the bat the exposition is filled with hard-to-follow terms like Fal'cie really doesn't help!
Many complained about its linearity... and even though it did feel too on-rails, it was ok. What kept me playing was the fact that everybody was saying "it opens up after 20 hours!". And yes it did. It stopped being a final fantasy and became something closer to WoW.
It's the only final fantasy where I had to use a trainer just to be able to finish the story.
obviously I don't mean any disrespect. De gustibus non est disputandum...