Why Lion and Queen Mary sacrificed a superfiring turret

Why did Lion and Queen Mary omit a superfiring turret rather than the amidships turret used in earlier layouts?

The machinery arrangement made that hull position more valuable for boilers, turbines, gearboxes, and shorter propeller shafts.

These ships adapted battleship concepts into faster hulls with much greater machinery demands. Boilers, turbines, and gearing needed a workable sequence inside the armored hull. Keeping the propeller shafts shorter also affected how efficiently power could reach the water. The sacrificed turret position was therefore a consequence of fitting the propulsion train, not a judgment that superfiring firepower was intrinsically less useful.