[om2]

They use of horizontal layout is to some extent a chicken and egg problem, since support for vertical writing has been poor in many web browsers.

Vertical writing is often used in books, however, including ePub books that are internally HTML. With good enough support, it would be pretty reasonable to do a vertical layout for a serious news site, and horizontal form controls in the middle of that would likely be out of place. Physical newspapers, magazines, books, and manga in Japan are predominantly vertical.