An interesting thing I noticed in the comments section of the article mentioned in >>1 is that somebody said that usenet was never really popular in Japan and that this may have contributed to 2channel's popularity.
If you take a look at the stats in >>11, you will notice that their usenet board (nntp) is one of the least popular, with about 50 posts each day, so the statement seems to be correct.
Still, I wonder why this is. Anyone got an idea?