And before anyone says "America joined WWII late," I want to say that's a lie by omission most of the time. It's true that America put troops on the ground only after Pearl Harbor...but the US government was already sending supplies to the allies before that; for the entire duration of the war, the US had an anti-Nazi government. Hypocritically so due to the US policies against black people, but some people phrase it in a way that makes it sound like they want us to believe the US was close to joining the Axis before Pearl Harbor (also bringing up the MSG rally, which...you could find a comparable amount of Nazis in any Western country at the time.) Anti-interventionism was the absolute norm in the US at the time.
Now, it is incorrect that US History class casts Americans as the primary heroes of WWII.
More likely, daisugi/copsing just doesn't yield enough to meet demand.