Complaining about game-length in almost any context actually irks me. Of course, I agree 60 hours of entertainment is still more than enough to ask for. Also, the existence of 700 optional missions and online play make the comment "there's nothing to do" seem simply retarded.
But even people who complain Ico is only 4 hours long. The game is an experience and making it longer would destroy the pacing of the game. That's like saying I wish the Inception was 10 hours long. If it was, guess what, it would have sucked.