As is often discussed here, you HAVE to plan for what your opponent could do, not what you hope he will do.
The U.S. positions in the Philippines, on Guam, and Wake all presented a clear and present danger to the Japanese strategic plan, something that utterly relied on establishing a defensive perimeter which would assure that no one would try to retake what the Lunge South had accrued or threaten the Mandates. Guam was less than 100 miles from the Jewel of the Japanese Mandates, Saipan. Wake, which was about 85% complete as a B-17 base, would have rendered the Marshalls untenable, and the Philippines stood directly on the SLOW between the Southern Resource Area and Japan.
No military officer could ignore those sorts of threats, not when planning a high risk, high reward operation where failure would mean the END for Japan as a modern military power (no oil = no fuel, no fuel = defeat in China. Defeat in China was unthinkable.)
The Japanese also knew, with 100% certainty, that within two years they would have absolutely no hope of engaging the U.S. The Two Ocean Navy Act authorized a fleet larger than any Japanese admiral had ever even dreamed of (this was, of course, the fleet that obliterated the IJN in 1944 and by the late spring of 1945 was launching massive airstrikes against Japan's Home Islands, finishing the insult by SHELLING the Home Islands from warship that were visible from Japan's beaches).
You HAVE to honor threats. Japan did.