I think first of all you realize that most American history books don't record the fact that upon the news he panicked and locked himself in his room for several hours mumbling reading his Bible, even his wife unable to snap him out of it. Obviously the Bible tactic wasn't working.

He was in a tough spot. If I recall correctly, his staff admitted he had been warned by intel and still didn't give the proper orders.

According to American weapons experts and intel, the Japanese fighters from Formosa couldn't possibly reach the Philippines and he was let down by typical anglo-saxon arrogance and self delusion of our own equipment, technology and all superiority.

I like some of the ideas mentioned above.
The Philipines are really a bugger to defend.
Unconnected isolated islands that require shipping to move your ground reinforcement from one area to the hot spot.
The Japanese landed in too many areas at once and contrary to our war movies showing regular infantry paddling to land on every odd kind of boat, they actually had some of the first specially made Landing Ships and LSTs etc.

Some neat comments above that I think would have done alot better, yes.