The message of William Blake's poem "The Chimney Sweeper" is not that children should work hard, but rather a critique of the exploitation and suffering of children in the society at the time. In the poem, the speaker is a young chimney sweeper who recounts his life of hardship and deprivation, forced to work at a young age in dangerous and filthy conditions. The poem highlights the injustice and cruelty of child labor and the lack of care for the well-being of these children. This is not a message advocating for children to work hard, but rather a call for awareness and change to the treatment of child laborers.