I don't think you can lump together an entire nation in one grouping. Nissan's recent WRC attempts may have been poor but IIRC they had a Fairlady Z do well in the Safari back in the '70s didn't they? I don't think the Japanese are any better or worse than the Germans or Americans. BMW may not get motorsport but the VW group (when they can be bothered) have done very well with ALMS or F3 and Mercedes have not done badly either.