It's mostly because of earthquakes, they got used to buildings being temporary.
Also sismic regulations are constantly evolving, so newer is safer (because more resistant to earthquake thanks to modern technics) and after some time it's more effective to destroy a building than do the necessary (and mandatory) work to keep up with the regulations.
So no, the Japanese don't want new houses because it's shiny and they're bored of the old ones.
It's mostly because of earthquakes, they got used to buildings being temporary.
Also sismic regulations are constantly evolving, so newer is safer (because more resistant to earthquake thanks to modern technics) and after some time it's more effective to destroy a building than do the necessary (and mandatory) work to keep up with the regulations.
So no, the Japanese don't want new houses because it's shiny and they're bored of the old ones.