Describe the theme of qualities of a good writer in the invisible japanese gentleman

The narrator is well aware of the difficulties a writer faces in making writing an actual profession. He notes that publishers are not always truthful, that they tend to exaggerate, and that publication often have no longevity, thus, royalties are limited. He also talks about how writing becomes more difficult over time, how one's skills in observation deteriorate with age, and that the time comes when one is judged by performance... not by promise.