If I may request that the truck be put in reverse for a moment, I fear some unnecessarily broad cultural generalizations are being made here. And while that's fine (this thread, and Professor Goldsbury's articles in general are basically about cultural generalizations as seen through aikido), I think it's important to provide some specific context to the terms being thrown about here, lest people get the wrong idea.
"Hikikomori", for example, is merely a Japanese term for a worldwide phenomenon of social withdrawal seen in many first world countries. It's prevalence in Japan has been distinctly overstated, first by the professor who coined the term and then by the BBC when reporting on it.
"Parasite singles" are, IMO, a tempest in a teapot, and perhaps don't really belong in this discussion. Single children living with their parents until marriage, even into their 20s and 30s, has long been entirely normal in Japan. Then some academic uses a catchy phrase to criticize this practice in the face of the impending aging crisis, the press picks up on the term, and off we go.
As for otaku, what is concerning about geek culture? Particularly on an internet message board filled with, if I may say, what could certainly be considered many "budo otaku".
Bosozoku, ijime, and to a lesser extent kyoiku mama, I see as definite social issues that Japan faces these days. However, if I may take up the (much trodden on) banner of cultural relativity, I don't know if I can agree with Professor Goldsbury's characterization of this as "cultural mania". (Although I suspect we are actually close together in our views, and this more a quibble over semantics.)
There's a tendency, I think, to make the fundamental attribution error
on a cultural scale. It's all too easy to look at some ephemeral social phenomenon and believe it says something about the culture in which it was born. I try instead to look at the economic and systemic context in which these phenomenon are born. Does Japan have "kyoiku mama" because of a particular cultural intensity? Or is it perhaps because mothers, naturally concerned about the future of their children, see this as the best way to work/game the system? And perhaps if we transplanted this system to another country, we might see a similar result.
Which is not to say that there aren't cultural factors involved, and that they aren't looking into. But just as it behooves us not to judge a man's character without considering the contextual impetus for his actions, so it does for us to consider the wider context of cultural phenomena.