Indeed, those are cultural differences. However, I don't think those are directly linked to nations. Even within a single country like Germany, I'm observing vastly different approaches to software development.

Also, issues like "Why don't you accept my (seemingly) working patch?" appear quite frequently in a lot of Free Software projects, independently of the nations of the people.

I guess this cultural difference has more to do with professionalism and long-term experience on software projects.