Those houses have nothing to do with traditional Japanese construction and joinery, those are just cheap houses built to fill an immediate need. This is a fairly common thing anywhere that is experiencing rapid growth, you either meet the needs of the people or they move somewhere else, you can't expect them to be homeless until their palace is built.

Edit: I said traditional and the thread is about modern, but OPs link is referring more to design than construction, very much uses traditional techniques with some variations to adapt it too modern tools. Good article.