I believe it's not just a Japanese thing but Asian in general, but I fail to understand the reasons. Some 16 years ago at a company I worked with we were testing some mini industrial PC and embedded boards for a project, so we had to download lots of documentation from the manufacturers site which was located in Taiwan. Those weren't home or business PC boards, their site target audience would be mostly engineers and…
Well, why do people have cultures might be the same question.