I too come into my reading with the viewpoint that the Philippines campaign was mostly unnecessary, and quite costly, and likely driven by Imperial Mac's insistence on being able to say "I have returned".
But …
I read the linked article with a passably open mind, and I feel it makes some very good points. The synopsis that Armand has placed on the OP lays out considerations that the article further amplifies on. I find these to be quite compelling.
Key factors that affect my thinking are:
Japan's most critical Sea Lanes of Communication (SLOC) to the southern resource area ran through the Philippines. … the southern resource area provided 75 percent of the world's rubber, 66 percent of the world's tin, and had initially given Japan self-sufficiency in petroleum.
Yes, there was a faster direct path to Japan from the US. But it would be exceedingly naive to expect to simply sail across the world's largest ocean, step ashore, and expect to find a quick white flag.
Successful strategic (or even operational) amphibious invasions require bases of operation and supply and isolation of the invasion area, so that the post-landing build-up can favor the invader. That's REALLY hard to do if you are coming from 5,000 miles away, and the enemy is on home turf with internal lines of communications and supply.
The only path to a reasonable expectation of success in attacking Japan directly travels through significant destruction of their fighting forces and their industrial support infrastructure.
If I were sitting on this strategic planning challenge in 1942/43, I can hardly imagine NOT taking away the connections to rubber and petroleum, given how concentrated the Japanese supply situation was.
Interdiction is one thing. Seizure / occupation is another thing all together. In Europe, if one looks at the German situation we see that no matter how much interdicting the western allies did, it was the Russian occupation of Romania (and the Romanian oil fields) that really shut off the tap for Germany's mechanized war machines. From that point on there was almost no fuel for training tank crews or pilots, no fuel for trucks to supply the troops, and German operations had to be very limited in scope or rely on captured petroleum stocks.
There is much to be said for cutting off the tap before you go in for the kill.
-Mark
(aka: Mk 1)