As a Japanese, I will mention that I've seen Japanese people correct each other on this, both in private and in public. Its because we might get the meaning by context, but if you pronounce it wrong, it sounds very strange in that context where its clearly wrong... To default to an assumption that this is due to racism / cultural gatekeeping says a whole lot about your world view and perception about Japanese people and culture than it does my people.

For example, examine your own words when you say that where you come from its a subtle form of discrimination. Well, you are saying it yourself that an action is deemed discriminatory according to the standards of your own culture, not to the standards of the other culture. You realize that could be cultural misunderstanding? There is a word for evaluating another culture by the standards of one's own culture: ethnocentrism.

If you are actually living in Japan, you should self-reflect a bit about what problems you face that you attribute subconsciously in your head to malicious intent, rather than cultural misunderstanding.

Anyways, I'm often disappointed by the comment section on this website when its anything about Japanese people. This is just another reminder for me to avoid the comments.