Perhaps I should elaborate: In larger battles, some of your turns can easily take 10 minutes or so to play. Which would be time just spent watching the screen for the other player. Also, a large battle with 2 human players will take hours. In my experience this doesn't work all that well even for hardened PC gamers playing games like Civ4, so I'd be really doubtful of it adding much for most console players.
Then there's the fact that it's an SRPG. The whole "RPG" aspect would have to be removed for fair multiplayer.
All that said, of course, all things being equal (which they wouldn't be, since development budgets are sadly not infinite), multiplayer would add to the game. I just hate the "every game needs multiplayer" mentality, especially concerning a title like this that is already the Game of the Year without it.