Could you provide specific examples of this bias in American high school and college curriculum? Looking at California 11th grade history standards, Pacific and European battles are both represented: "Explain United States and Allied wartime strategy, including the major battles of Midway, Normandy, Iwo Jima, Okinawa, and the Battle of the Bulge." Based on this, the gaps in US WWII historian education seem to be things like the China-Burma-India campaign, Operation Torch, the Italian campaign, and the Battle of the Atlantic.

Ultimately most US Industrial capacity went to the European front first. Take a look at one of my favorite webpages, Parshall and Tully's Economic Realities. Simply put, Germany had 4-5 times the industrial war making capacity of Japan, while the US had 3 times the economic capacity of Germany.

In addition, let's take a look at the battles that are typically examined in a high school history unit. Just using my high school syllabus as an example, we have:

Invasion of Poland

Invasion of France

Battle of Britain

Operation Barbarossa

Pearl Harbor

Midway

Guadalcanal

Stalingrad

Operation Torch/Kasserine Pass

Operation Overlord

Battle of the Bulge

Iwo Jima/Okinawa

As you say, 8 out of the 12 feature Europe as the primary theater, while 4 out of the 12 feature Asia as the theater.

But what is the US role in framing the war like this?

The first four set up the war in Europe as being an imminent threat to all Europe. Germany, having rebuilt its war machine, invades Europe and is virtually unstoppable, barely being halted at Britain and at the gates of Moscow.

Then we have Pearl Harbor. A dastardly, unprovoked attack by the forces of the Empire of Japan, Day of Infamy, etc. Then we have vengeance on Japan at Midway, for foolishly thinking she could beat superior American forces, and then the beginning of the end for Japan at Guadalcanal. Then we have the great battles against Germany, ending with the final defeat of Japan at Okinawa and the atomic bombs.

The end result is that, unsurprisingly, we end up with a strongly pro-American view of the war. It sets up the narrative for the US saving the world from evil aggressors, and it couldn't have been done without us.

Now let's say we start adding some vaguely important Pacific War battles to the narrative. Here's an easy one: Leyte Gulf.

Leyte Gulf was, simply put, an unmitigated slaughter of the Japanese Navy. One of the least coordinated naval forces in history was ordered to make an extremely convoluted attack involving the sacrifice of all of Japan's remaining carriers and a pair of old battleships to stop a bunch of landings in the Philippines. The sad part is, it almost worked, because the US "fell" for the carrier "bait." It doesn't contribute to the narrative, or for that matter, any narrative, other than that the IJN was a clusterfuck of suicidal idiocy who failed to understood how attrition worked.

What about expanding Guadalcanal to the naval operation? Then we would see an extremely bloody slice of naval warfare, such as 1st Guadalcanal, where an American cruiser force succeeded in protecting the air field at the cost of virtually every single one of their ships damaged or sunk, 2nd Guadalcanal, where a lone Japanese battle cruiser fought two US battleships and almost won, Santa Cruz, where the US managed to lose a carrier and had another one damaged for two damaged Japanese carriers, and other battles that just don't explain any sort of story, just bloody warfare that failed to achieve any objectives.

Basically, none of the battles had any real impact on how the war was fought after Midway and Guadalcanal. So there's no point to talk about them.