Pretty much everything has already been said.
I'll just say that FFXIII's 20 hours long tutorial doesn't do it any favors. You are stuck with only 2 characters for way too long.
Also, Lightning is just unlikable. The story's focus is on her (even moreso in the sequels), while she does everything to make herself unsufferable. And she was choosen as the game's "main" protagonist anyway. She is the perfect example of how not to write a main character: she is bitter, annoying, self-centered, aloof, violent (physically at least), snarky (but not in a fun way), she doesn't think things through (she basically throws a tantrum and just moves forward because she is vengeful and doesn't want to stop and think about all that happened ~ not until Palom-Porom anyway), she treats others (including her own family) like shit, and so on.
Were it not for the fact that, gameplay-wise, she is a powerhouse, no one would have kept her in their party.