I can tell you that nobody who ever wrote poetry did it to become rich. Even walcott and heaney had extra jobs. The question then becomes, does it give you any pleasure to write this poetry?
Some people, average painters, spend a lot of time painting apples, sunset elks and weeping children. When they are done they proudly display it in their living rooms, not because they think they are Da Vinci, but because they felt that they mastered something new. If somebody then shows an interest...fine.
Neither Kafka, Lovecraft or Van Gogh imagined the fame they got after death. Yet, they kept at it. None of us are at that level, but at least it shows that even very capable artists were motivated by something else.