Agree entirely with your view that buying a new house in Japan is a massive waste of money. A couple of points though.
1) First, land prices are going up in Tokyo, albeit slowly, and there are some hotspots where they are rising quite rapidly. I doubt this will continue as Tokyo's population starts falling after 2020, which may be an argument to buy as close to the centre as you can afford to.
2) Secondly, I'm a bit dubious as to your comment about the high quality of Japanese houses. If they were so good, why are so many pulled down after 30 years? I think there's a difference between earthquake-resistance and quality, to be a bit facetious, a cardboard box has excellent earthquake resistance but you wouldn't want to live in one!.