Anyways, I don't see anything special here. Just standard western nationalism-exceptionalism if that makes sense.

I think it's more than that.

Symbols associated with colonial projects can bring up a lot of generational trauma in countries that were on the receiving end of the atrocities performed by past colonizers. This is something that is easy to overlook for outsiders from countries without that history.

The effects of Imperial Japan on the East Asian countries were significant, particularly for China. Remember, WWII began in the 1920s for China and arguably half of the fighting for the entire war occurred in China along with war crimes and atrocities or imperialism that were never repaired and are largely overlooked in the West. Some countries in the region managed to eject imperial Japan just to have the Western Allies bring the same Japanese officers right back to run their new colonial projects after "liberating" the East.

The hard feelings toward Japan are deeply rooted in a bloody and violent history of subjugation that has never seen apologies or reparations made. While US POWs can say they too experienced trauma from imperial Japan, it's nothing compared to what the people of East Asia experienced every day in their homes. The trauma has a different, deeper nature and this is easy to overlook from an outside perspective when viewing the original post.