I expected that kind of remarks. Contrary to Western and Korean beliefs, Japanese researchers aren't obsessed with shitting on South Korea 24/7. There's a lot of individuals genuinely interested other languages and cultures, studying things like the Korean speakers in China's Yanbei province. In the article I linked, there are more references to research articles on the topic written by Japanese than what exists in English.
I can't blame them because it sure looks that way to people who's exposed to Japanese online culture. The ever-growing netto-uyoku (far right trolls) and the general public's reluctance to challenge their views is a problem that's been allowed to continue for far too long since the 2 chan days. Japan needs to find a way to de-radicalize these trolls. Even more so now that corrupt politicians are manipulating them to escape justice [1][2].