Kleon calls attention to how our culture sees any of one’s creating as money making. While a friend might intend their comment about the gift one made as a compliment suggesting the artist could sell it, not every creation needs to find a path to be sold. He cautions the reader about these changes in our social structure of turning a hobby into an additional job. The task of creating becomes used as another form of praise heaped on to people. The message becomes - free time (hobbies) must be used to gain additional income. He suggests to find one’s passion, and not monetize it, as this is what sustains one's spiritual nurturance. Creating is not to be used to measure one’s worthiness.
I encourage you to buy a copy of Keep Going for a better understanding of your own creative process. Whether you're a master artist or beginning artist, this is an excellent book.