Well it depends what you mean by “so prideful they refuse to accept outside cultures and ideas”
When you go to Japan you can see a huge impact made by western culture: clothes, fashion, media, architecture, food, to mention only a few. Here’s a small excerpt from a historical text:
After the Meiji Restoration, the West was taken as the supreme model for nearly every significant aspect of life, and many insignificant ones too. Popular assemblies, government bureaus, schools, the banking system, clothes for policemen and military men, and the pre-1945 constitution, all were based on one or other Western examples. Hair for both men and women was re-styled according to European fashion; beer was brewed as an alternative to sake; beefsteak, baseball, and the cravat were considered smart.
The very business model you were criticising for being unable to accept foreign ideas or influences is itself a foreign influence that has been assimilated.
The country still has a very strong cultural identity, yes, and they work hard at keeping that alive. To call an entire country overly prideful to the point of rejecting anything non-Japanese though, it’s just simply not true.