It’s not an author choice, it’s a publisher choice. More than one author of a book on classical music has complained in recent years of being unable to include examples from the score in a general-audience work because the publisher thought it would scare potential readers away. You and me might think that a reader incapable of reading music might simply ignore such score examples and continue reading, but publishers fear that the mere presence of a score example would make the book seem to highfalutin’ for most audiences.