Gaijin is a funny word--it means "alien" or "foreigner" but it's actually a shortened version of the proper word 外国人 "gaikokujin". As such it's kind of slang, and one of those words that some of us use with each other in good humor, but don't usually like hearing from Japanese strangers.
In any case, there are a variety of us that come from abroad and make our homes here. As much as it's not always nice to compartmentalize people, there are two main "types" or perhaps more accurately, stereotypes of Western foreigners.
The first type loves Japan and loves living here. The second type doesn't. Those of the first type generally are single, have some place to work and/or study, and see Japan from the point of view of a fan. "Isn't this crazy and funny and wonderful?" Maybe they have a lame job or trouble making and keeping Japanese friends, but there's something about the Japanese lifestyle, or the town they live in, that's captured their hearts and allows them to stay positive and bridge that cognitive dissonance of my favorite country that I'm making big sacrifices to live in has warts.
Then there are the bitter old expats who've been here forever. Usually they started out as one of the above gaijin but they stayed too long. They've seen the good, bad, and ugly of Japan over many many years and they've lost sight of the good and are burnt out. They may have wanted to immigrate or raise a family here, but their values didn't match up with what's on offer here. They have a lot to say about Japan but little of it is positive. They get criticized for being too negative, and being unable to have a balanced view. This country that I sacrificed my whole life to has too many warts to ever be my favorite.
Since getting married to a Japanese I find myself moving into the second category. I thought it would take more years to get there, but having a Japanese spouse is like a shortcut apparently. I don't like it. I don't want to complain or compare Japan and my home country too much--of course things are different, it's a different country!
Perhaps the problem isn't that there are these two types of foreigners, but that there are at least two Japans. It's not all our fault; it's the huge gap between the way Japan presents itself to gaijin (often assumed to belong only to the "tourist/big fan of Japan" category, indefinitely) and the way Japan actually works for Japanese people. Japan makes itself easy and pleasant for gaijin in a lot of ways. We're not held to the same standards as citizens by any means, and there's this weird culture of "entertain and be entertained by the foreigner". Oh, where are you from? Which famous sights have you seen? Can you use chospticks? Do you like Japanese food? Oh wow you like karate...
Our role in Japanese society is to experience and to enjoy. It's certainly not to participate, it's not to join as a member, it's not to see the real systems of workplaces and family dynamics, the secret everyday life of Japanese people that has no place for a foreigner, secret to us thanks to our low-context mindset.
Is it the gap between the two Japans that causes such bitterness from some long-term ex-pats? Is it because we always have a different way of living (in our home country) to compare life with? Is it because ex-pats are actively discriminated against and excluded from membership in society? I think for me, the reason is closer to the first two. I can always compare Japanese values with the values I was raised with and think, "No, I know a better way to do this" or "this doesn't have to be this way." And then of course, like a good a little liberal arts student, I blame myself for the sinful thought and frame it more politically correctly: "Not better or worse, just different" "When in Rome..." and worry I'm losing positive thinking.
In the end however, I wonder if bitter ex-pats get put in a bad light simply because they are vocal about their discontent? I know not all Japanese are always satisfied and happy with their own culture. Even if I'm becoming one of those lame gaijin who's critical of Japanese society, I don't think I'm alone. I don't mean other foreigners are thinking the way I do. I mean there are many Japanese who share some of my frustrations about life here--things like the work culture, the family life, etc. I know this because I belong to the Christian community--a tiny minority with a vision of a different way of living that doesn't always follow the norm--in Japan.The difference is, I sometimes talk about the things I don't like, but that's a big no-no in Japanese education where 我慢、patience under adversity, and 迷惑をかけないこと、not causing trouble for others, are the rule of the day, even in church. If Japanese people are not happy with the systems they've created, very few get vocal or try to change things. Most just burn off stress with a hobby or odd habit. They just think "ah well, adult life is tough for everyone" and make do. For people like me who know a different lifestyle and can always go back to it, it's hard to accept. To be honest, I'm afraid of the kind of people we would become if we did. I don't want to be one of THOSE gaijin. but maybe they are just a kind of canary in the gold mine, and my feelings are not only due to a lack of positivity or sufficiently open-minded thinking in myself.
I mean, let's think of Japan not as a place to be endlessly entertained or as a place where our dreams come true, but try to look at it the way it is for Japanese people. I think it's sometimes totally different from the way a lot of foreigners perceive Japan. For one thing, there is a feeling in Japan that if you're enjoying life a lot, you're not doing it right, and that suffering and stress is actually a sign that you're a good, serious person and a hard worker who is doing their part. Maybe sometimes we foreigners get stuck on the first "pretty, fun Japan" as presented to us and then when we're here long enough to get close to joining the system and experiencing the country the way Japanese people do, we undergo a kind of shock...I do think my culture shock deepens the longer I'm here and it's actually not a shocking or uncomfortable country right off the bat (or boat).
I think this is why some ex-pats get very bitter here. Because the Japan shown to visitors and the Japan for Japanese people is so different. It's so natural and obvious but there it is...a possible source of major discontent for long-term expats, who may also appear more dissatisfied than the Japanese simply because we voice our feelings more.