The Japanese definitely have a different outlook on game development. Far more of them see making games as prestige projects than straight up money making endeavours. Money is still a factor, but it isn't a main driver in a lot of the games. Hence why a lot of games that don't play or sell well tend to come off as failed experiments rather than commerial drivel cash in that is out to fail.
There is also a strong export filter effect that that prevents a lot of shovelware that any development community produces from reaching the west creating a natural bias.
Then there are the games that don't have a natural market in the west. Your Hentai games, dating games, the overly complex near unplayable tactical RPGs, the ultra grind based RPGs, bullet hell shooters, visual novels, mech games, anime licenses.