I'd say it stands out because people have a warped image of what Japan is like. Having lived in 3 major cities in Japan, I find their webdesign completely in line with their print design, architecture, popular music and store design (both front and interior) and most apartments I've visited have been a far cry from the minimalistic lifestyle people often associate with Japan.

> such as modern architecture or industrial design.

Except for some landmarks, temples and gardens, contemporary architecture in Japan is surprisingly ugly and noisy.

I think most of the big sinners of Japanese webdesign are stores (at least the examples I can think of) and something like Bic Camera is more noisy and flashy in real life than their web presence.