There are multiple books and papers written about what happened in Japan in 1989. It's no surprise that a small market like "lugged bicycle frames" started to go away during that period, especially with newer technologies and cheaper building processes starting to emerge. Japan was never a huge player in that field in the first place as they did not have the heritage, master frame-makers nor make anything superior to their competition (like they were doing with cars and motorcycles throughout the 70's and 80's).