I haven't read Kafka on the Shore yet, but it's my impression that Murakami very much imagines himself as a public intellectual (which is a much easier persona to don in Japan than in the States), or at least he did around the time he wrote The Wind-Up Bird Chronicle--it's my interpretation, anyway, that the nauseating scene in that book is very intentional, since Murakami, I think, wants his (Japanese) readers to confront the things that they're trying to forget, and he's using the nausea to that end.