Actually, despite the naysayers, XII's form of ATB is built off the X-2 system (it just added the ability to move around and dropped the finicky combo system) which itself is closer to the original FFIV system (though greatly sped up) that predecessors dropped from V onward.

Its true that SE has never truly moved away from ATB but it is apparent with X-2 onward, their has been a serious effort to make the system more like an action game, to the point SE has decided its so fast you're better off having A.I. and pre-programmed commands cause its too much for man.