The trouble with publishing a book, from a first-time writer's point of view, lies with the slowness of the publishing industry. Once written, the book has to be accepted by a publisher, rewritten according to the editor, then scheduled, manufactured, distributed, and marketed. Most books don't get much in the way of marketing.
Years later, with the very best of luck, the author begins to see some small reward for his efforts. Maybe $5,000 if he or she is very lucky. If your first book isn't profitable for a publisher, you may never have the opportunity of having another published.