I listened to an episode of the BBC Radio programme Digitial Planet in which they expressed amazement at the use of contactless payment cards like the JR East Suica cards, and could only come up with the Japanese love of technology as an explanation. Although that might be a factor, what is much more important is that Japan is still a cash society, with debit cards rare and credit cards needing to be paid back in full every month. A scheme that is basically cash but also a card is therefore perfect for Japan, and if people think a similar scheme will take off in London and so replace debit cards, I think they might be disappointed.
And not metal like Korean ones?
According to a book on Korea I read and then forgot the name of, Chinese ones are longer because they are more likely to eat very hot food that could spit oil all over your fingers if you don’t keep your distance. The Japanese couldn’t use metal chopsticks because until comparatively recently for all but the rich their rice was almost always mixed with other grains such as barley, making it less sticky.
Not 100% convinced with this explanation, as anyway the Koreans are supposed to use their spoon with rice rather than chopsticks (though this taboo is disappearing), so as ever contributions from others very welcome indeed.