The argument for procreation takes a very objective, evolutionary stance. Humans are not objective; we have bias, emotion, conflict, and differences. These aspects can supersede the need to procreate with other priorities which define their respective purpose of life.
Several humans cannot or chose not to have children, but their lives still have purpose. For example, many members of the LGTBQ+ community do not have children biologically. In addition, many people who have changed the world did not have children including Leonardo da Vinci, Vincent van Gogh, Julius Caesar, and Socrates. The argument for procreation suggests that the lives of these people have no purpose or value since they did not have children. Of course, the previous notion is false.