Historically if you look at the most popular FF games, (VI and VII and IX) and the least popular post-NES (X-2, XIII and V) I think that it starts to become clear what people want in an FF game, even if I think XIII is one of the best, the reason people love VI and VII are because they are easy games at their core but have fantastic exploration in rich worlds full of lifelike NPCs (for their time). The games with far superior gameplay over them (V and X-2) are less popular and lack these things, XIII fits right next to them when you consider this. Perhaps if these games were titled something else and people bought them without expecting exploration and whatnot, they would have much better reception. As it is, some people have already gone back to all 3 with different expectations and found out they really loved the games they just weren't "good FF games".