It might be easier to take a look a look at the Wikipedia page (http://en.wikipedia.org/wiki/Category:Video_games_set_in_Japan) for games that do have a Japanese setting and then just listen to the soundtracks for all other games. 😀
the reason they do this is most likely to do with classical training and a complete adoption of western cultures.
Snake Eater from mgs3 is a good example. As it copies the style of a James Bond film (apparently).