Yeah, North America.
idk my bff usa
PS: Japanese players who can read / type in English should most on Smogon more so we can get a worldwide community going =) If you're reading this, post!
Lack of confidence in one's English certainly plays a role, but I think this is more of a cultural difference than anything else. Japanese people are shy and don't really feel comfortable posting information about themselves for public view, even if it has nothing to do with self-PR. Modesty and restraint are parts of it, but I think internet and impersonal communications are discouraged in Japan, mostly because of the misunderstandings it can cause between strangers who have never met.
There are large information-centric websites in Japan (pokemon underground in Tokyo, and pokemon inshuu in Osaka), but they are location-based simply because their members use the internet only to spread information, preferring to meet offline monthly for more personal matters like battling and finding out about each other. THey'll use the internet for posting factual information and working together for their manuals (think Smogon pokedex in book form), but they feel much more comfortable -- as would I -- sharing more personal and more readily misunderstood/abusable things like opinions and personal information, face to face. They do twitter and text results back and forth extremely personally and rapidly, but they do so with people they connect with personally, which goes back to the idea of favoring face-to-face interaction to internet chatter. I think the internet resources (RNG resources, etc) are so overused in Japan that players are afraid of posting personal information -- hence the use of handle names, like Saburou (Isao) and Midori (Yasuki) -- for fear that it, too, is abused among strangers. In fact, I met a few Pokemon players outside the center in Osaka that more openly request players' personal information and trade it over the internet, and those players have been blacklisted from most major groups.
~Halordain