When it comes to idealisation, there’s the feeling of grass is greener as well as hopeful in the romanticism of such a person or country as to be unspoilt by terrible realities or in Japan’s case, not letting reality get into the fantasy of it as I suppose. Something like expecting Japan to be all anime land, if because a lot of anime’s produced there.
Actually from my own experience going to Japanese language websites, albeit not in topics you’d expect to, there’s actually room for Japanese who’re indifferent to anime at the very least where there’s room for sports, feminism and ecology as far as I’ve remembered going there however meager as my memory gets.
Likewise, if you look hard enough there’s a lot of geekery in places like Brazil and Kenya where there are even anime fans and cosplayers there so it does feel overlooked globally speaking in favour of Japan’s anime industry even if Brazil and Kenya have their own comics and cartoon industries.
(Something like Kenya’s Shujaaz and Brazil’s Turma da Monica, but that involves any real familiarity with those.)
Not to mention, if you look even harder Kenya’s got Alokohan, South Africa has Supa Strikas and Cote d’Ivoire’s got Aya de Yopougon but I’m afraid African comics aren’t that widely accessible compared to Japanese ones. (They do exist if you find them either by deliberation, or by luck in some cases.)
Alternately speaking, Japan’s a normal country if you look past anime and certain subcultures, thusly going for the more common aspects like sports and other experiences like mental health and bullying. But that also demystifies Japan a lot, to the point where it’s ultimately no different.
The fantasy’s over, now comes a grim reality that’s too close for comfort. Frankly, I’ve been through something similar before and I suspect if some anime fans did bother going through things about Japan they didn’t expect, disappointments will come to them as well.
This is like thinking all Japanese love anime, but some of the Japanese people you end up encountering in the flesh aren’t all that fond of anime and some may even prefer live action to animation (J-Dramas are a thing among some people, however they’re not as popular as anime.)
That’s going to disappoint you, especially if you love anime a lot yet not all Japanese are fond of anime themselves. But I suspect that takes a lot more experience and knowledge to get over things, before moving onto others as I’ve done this before.