pictured: Sphaerophoria scripta on a Hawkweed flower (Hieracium sp.)
My man Daniel Saunders turned me on to this article:
It's about why scientists should write books, and not just scientific articles. I agree with much of what it says, but it misses some important points.
Scientific articles are written for your scientific peers. There is an understood jargon. This makes for efficient communication with them, but the cost is that nobody else can understand them. You rely on science journalists to communicate with scholars in other fields and the public. In a book, you can write for the public. Why would you want to do that? First, it's important that the public be educated about scientific matters, so that they can make better decisions for themselves and their governments. Second, it can inspire them to become scientists themselves. I know several people who went into AI because they read Hofstadter's Godel, Escher, Bach. But not only are you able to write for the public, you are writing to scientists in other fields. Cross-disciplinary interaction has been shown to produce better science (Kevin Dunbar's lab found this). By writing books you are contributing to other scientists' general scientific knowledge.
Books can contain book-sized ideas. And you should be thinking of book-sized ideas. If Darwin's big evolution book had been an article, it might not have had enough detail and evidence to be so convincing. If, as a scientist, you commit yourself to writing a few books during your career, perhaps it will encourage you to think of big ideas in the first place. Don't just wait for a book idea to come to you.
There are cultural reasons not to write books, particularly for the public. Carl Sagan got hammered for writing popular books. Others, like Pinker, seem not to have suffered. Psychology has a culture of not valuing anything except journal articles. Books and conferences barely count at all, the the merit system. Play the game, write your journal articles. But don't be a dust-bowl empiricist, don't eke out a living making incremental contributions to your subfield. Especially after you get tenure, think big. Big theories, crazy theories. Throw some spaghetti against the wall.
And don't criticize others for writing books either. With hope this post will have convinced you of its importance, so you won't think badly of them. But even so, beware of prophetic discrimination, which is discriminating against someone through anticipation of others' discrimination (for example, you might not hire someone who writes books because you think others down the line will discriminate against them for tenure and promotion decisions, for example.)
Don't decide whether or not to write a book, decide what your book is going to be about.