Sartre's great error was assuming that removing objective values meant that life was absurd. Nietzsche almost made the same error with his metaphor that "god is dead," but realized that meaning comes from our own personal actions, from subjectivity rather than objectivity. Through personal actions by many people, values are created and become objective realities. There is no need for the idea of god or its replacement idea of science to buttress objective norms. There is also no need to attack the idea of god (though bigots do that for different reasons) to assert the human-centric reality of values. Life has no intrinsic meaning but that doesn't make it absurd unless one clings to the notion of objectively transcendent norms.