Final Fantasy XIII is definitely underrated. It's not the best FF game, but it's far from what people make it to be. It's basically the same as the older ones, just without pointless backtracking. People call it bad because of it's linearity, but I can't see how it's different from FFX. Why does everyone want all games to be open world? FF is story driven, unlike those open world sandbox games that have a short story and various side quests. If someone wants a fantasy open world, they can play the Elder Scroll series. Post apocalyptic open world game - Fallout series. FThe only difference between XIII and the older ones are cutscenes. Older games didn't have much cutscenes, but had heavy dialogues. FFXIII just puts those dialogues into cutscenes.
I can understand if someone who doesn't like Final Fantasy dismisses the game, but I can't understand Final Fantasy fans who dismiss it.