I couldn't really give you a satisfactory answer on that one. Why did Squaresoft insist on making the controls in FF Anthology un-customizable, but then decide to change that for FF Chronicles, and then decide to go back to the set-in-stone control scheme for FF Origins? Probably because they're Japanese and insane, two traits that are genetically inseparable, proven by such cinematic wonders as "Urotsukidoji" and "Water Closet 2".