The problem entails that linearity in RPGs has been in story progression as someone mentioned before. However, past games in the series usually required you to finish a linear segment of the game at the beginning and then opened a huge world for you to explore. That's what opened the imagination of the players even if the story was always going to the same place everytime. Ever since FFX that has stopped. FFXII was the last game that gave you a certain amount of freedom.
In conclusion: Yes, I have the right to bitch and complain about something I haven't played because we have "experts" (read professional magazines) telling us this game is too linear.