Is there any reason to believe that if this plant had been using the best known technology and was built to withstand the worst case "expected" scenario that things would be any different? Sometimes shit just happens. Japan needs power. Nuclear energy provides an economical option. What other options (safer options and think Exxon Valdez before you answer) were available when these plants were built?
Just a thought. And I don't subscribe to to the irrational diatribes about greed and politicinas. The people of Japan chose this option. As have the people of many other countries including the US.