I find the comparison with SE Asia rather poor with regards to investment as I've been to Sri Lanka and the amount of money that is available for basic infrastructure, let alone anti-tsunami barricades, is negligible compared to Japan unfortunately.
Interesting way to put it (implying that the issue was behavioral/cultural rather than one of engineering)
Japan was much better prepared because they have been facing this so long. Blaming this as a behavioural/cultural thing is ridiculous. I would bet that all the South and SE asian countries are better prepared for the next tsunami. We have been already through multiple tsunami warnings from then which did the job pretty well.