Legendary Nintendo game designer Shigeru Miyamoto has told Entertainment Weekly that he believes Twilight Princess didn't do well in Japan because there are fewer and fewer people interested in playing big RPGs.
When asked his opinion on why Zelda isn't doing well in Japan, Miyamoto replied, "Well, I think a lot of people who bought the Wii are not necessarily the types of people who are interested in playing that kind of game. And a lot of the people who would want to play it [due to chronic shortages of the console] can't find a Wii! But mostly, I think it's that there are fewer and fewer people who are interested in playing a big role-playing game like Zelda."
In the interview Miyamoto also expressed his wish to create a game that makes those darn kids respect their elders: "In Japan, there are a lot of trains that have sections reserved for the elderly or pregnant women. Young people in Japan sometimes sit in them, but if people come up and need them, you are supposed to get up. But most of the kids don't! It really upsets me. If I could build a game that somehow made the young people respect their elders...
"And there is another issue bugging me. In Japan there are a lot of people who freelance or work under the table - people who don't pay any taxes. I look at places in the world where people understand that paying taxes to the government helps society. In Japan there's not that understanding. So [social responsibility] is yet another issue I might address in a game. But I probably sound like an old man when I bring these things up."
Read the full interview here.