There are 2 types of Japanese Culture Fans:
Only two types of people who are into Japanese culture..? You're really sure you can't boil it down to just one type, and make it even more accurate, precise, and all-encompassing in terms of describing the thousands of thousands of people who are into the numerous aspects of Japanese culture, old and new, of the past and of the present? ...
Look... there's lots and lots of different "types", if you want to call it that.
I myself with regards to Japan, have an interest in idols, various aspects of popular subculture, entertainment, music, movies, culture, history, religion, literature, society, traditional art, architecture, and probably more topics that I forget right now. Some I care more about than other, and with regards to the aforementioned I'm into, there are certain topics I care more about than others. For example with Japanese history - which really is a vast field - I am more interested in Classical and Medieval Japan rather than say the Meiji Period, although the Meiji Period is really fascinating. I read about these things, watch or listen to relevant media, and all of that jazz.
But I don't think that everything Japan is amazing and that everything else not being Japan sucks, nor do I love everything about Japan. In terms of things I like, study, read about, immerse myself in and so on, Japan isn't even number one for me... There's a couple of other countries and issues related to those that I am far more interested in than Japan, and have been for years since I was a child.
This phenomena isn't limited to just Japan, you can find it around the world with regards to other countries or topics that people go way overboard with, and completely lose the plot with. I know of South American black metal fans that are surprised when they come to Norway and finds out that their heroes so to speak have regular parents whom they meet with, or maybe are parents themselves, or are school teachers, and are well functioning human beings of society, and don't constantly wear corpse-paint or walks around looking angry and so on.
And what about some of the Japanese people (girls in particular) who thinks that France = Castles, and romantic princess or whatever. I mean, this is a rather naive and limited view to have isn't it?
It all just boils down to doing your homework, i.e., becoming informed, objective, being open-minded, trying to look at things from different angles, and not being lazy. A lot of people refuses to do the work needed to attain more knowledge about any given subject. And that's their downfall.