it doesn't have to do with a bias. Sequals sell in Japan. Established names sell well in Japan. Good marketing sells well in Japan. You can't simply release a good game and expect it to sell well in Japan, it has to be backed with appropriate marketing and appeal. Japan buys games like Ridge Racer and Daytona USA because they trust the names.
currently playing: Skyward Sword, Mario Sunshine, Xenoblade Chronicles X