Japan should take tsunamis into consideration when building because the effects of such natural disasters are now well-known. It is safe to assume that there will be future tsunamis that will damage or destroy coastal areas. Future development should be redirected to inland areas in order to prevent loss of life in the event of a tsunami.
Japan has a history of water-related natural disasters damaging it, and as an island with cities near the coast, the water is an even bigger concern. Modern technology can protect against the elements but only to a certain extent. It would be foolish and dangerous of Japan to disregard those warnings.
How Japan allowed nuclear plants on their coasts? They are in coastal regions because water is presently how they cool the systems. Someone famous said that they were okay with a little loss of life for the sake of nuclear power. I wonder if that person understands the full impact of recent nuclear disasters. Pripyat, for instance, is still completely uninhabitable and it's almost 30 years after Chernobyl. There are estimates that say it will remain uninhabitable for at least 200 more years. Even if you could repopulate the place now, you couldn't eat anything you grow there! We don't even know how many people in Belarus are ill or have died from the disaster. How many "zones of alienation" will our planet end up with? Is that worth the quest for nuclear power?
They should immediately stop because there is much knowledge to be gained from our elders. They did not just write that advice and warn about tsunamis for the heck of it. People need to stop rolling the dice with Mother Nature and use common sense when it comes to natural disasters.