4) It’s too hard and would take too long.
It took the team that made the movie Advent Children one year to get the graphics as good as they were and to render the cinematics. In that movie, there were only 3D sets of the Sleeping Forest, Midgar (and this was only an exterior view of it), Tifa’s house, a highway, and two towns. Only the sprites for the main cast were made. For a game that would be released on the PS3 or XBOX 360, not only would they have to make a whole new Midgar, they would have to make over an hour of brand new CGI cutscenes, 3D sets for every part of Midgar, as well as sets for all the towns: Kalm, Junon, Fort Condor, Costa Del Sol, Gold Saucer, Corel, Rocket Town, Wutai, Cosmo Canyon, Bone Village, Icicle Inn, the Chocobo Farm, and every dungeon and forest in the game. Then they’d have to make sprites for every character in the game that wasn’t in the movie. Then they would need to redesign around 200 monsters and 70 bosses, all the battle animations for them and the 3D sets each battle takes place in. Then they would have to fix that Bizarro Sephiroth fight because it was way too easy in the original game. They would have to update the music. Do voice acting for approximately 500 pages of dialogue. And so on. How long would this take?