I agree.Kurita's failure to 'go for broke' and instead retreat never made any sense to me, given that the IJN was at the 'use it or lose' stage, of which eventually happened in the aftermath of that battle into 1945. Japan gaining an extra month of time at the cost of the entire Center Force would have been much more worthwhile than letting those surviving assets get destroyed piecemeal with little effect on their opposition.
He had made such good decisions to that point...particularly coming across the Sibuyan Sea. He turned back under the air attack, and the US forces thought he was rtreating. When the aircraft ended theit attacks, he then doubled back and thus came through San Bernadino Straits completely undetected...and was not see until he was already in range of Taffy 3's carriers the next morning.
His first mistake...which I believe led to the others...was to order that general attack. It was not coordinated and did not take advantage of his immense advantage.
Pretty much small sections of ships, and individual ships, attacked (and maneuvered) on their own.
It allowed the US aircraft, and the US destroyers/DEs to attack and have a much better chance to get in close where they could use their torpedoes, and rake the decks of he larger Japanese ships with their 5" cannons.
But even then, when the DDs and DEs were spent, Kurita could have called his ships back into formation and proceeded. Instead, he withdrew and took three hours deciding to make it permanent...and then left.
If he had pressed on, that force would have caused immense damage.
I believe he honestly thought that he would be annihilated like the southern force if he pressed on and figured he should save at least something. Problem was, except for the continuing bothersome air attacks from the Jeep carriers, and the ferocious attacks of those few DDs and DEs...there was nothing to indicate that his annihilation would be the case.
But there are to this day reports that Kurita thought the DDs and DEs were light cruisers and the vanguard of the American battleship force.
But the US battleships were far away...with Halsey going after the Japanese carriers, and with Oldendorf, down south by Suriago Strait having destroyed the southern force under Admiral Shima.