Yeah, this was pretty early in the war, and I believe they were intending to show it was the first taste of combat for most, if not all, of the characters that were focused on. I believe GC's 6 months or so after Pearl Harbor.
The episode tried hard to show a lot of different perspectives I thought... A soldier with a consience, those without, etc.
They were very distinctly showing the prejudices and preconceptions driven into the heads of the average American as well. When the wounded Japanese Soldier kills a medic and rifleman with a grenade as they tried to help him, one of the Marines watching calls him a "Yellow monkey", which was an image that really was used in propoganda of the times. They were considered sub-human, and closer to a primate in a way.
I think as time went on, and wounded soldiers returned home and took up training jobs within the corps, that those views were being driven out of the minds of soldiers... or at least some were trying to wake up the FNG's for their own good that the Japanese weren't weaklings/inferior fighters.