The bias you speak about is evident in the article's title. "Why Japanese Web Design Is So ... Different". The baseline is by implication English design, since

The bias you speak about is evident in the article's title. "Why Japanese Web Design Is So ... Different". The baseline is by implication English design, since the article was written in English. Probably also some subset of English sites that the author feels is representative, and expects his/her readers to resonate with. This is fine, but the problem is that this bias is not made explicit. It feels a little like asking "why are all these foreigners speaking funny languages?" Since Japanese sites apparently look like they have not evolved since they were last like English sites around 1998, the better question might have been what factors have been driving evolution of English sites which did not affect Japanese? You may add other languages, but I'll just stick with Japanese since it is referenced by the OP.