Why does Fitzgerald try to emphasize at the end of chapter seven?

Daisy's carelessness and stupidity eventually lead to the death of Myrtle Wilson, and Gatsby is forced to leave the scene of the accident and to hide the fatal car simply to protect Daisy's fragile nerves. His decision to take responsibility for Myrtle's death reveals that his love for Daisy is unassailable; her cruelty has changed and will change nothing. Gatsby, despite his criminal activities, remains essentially noble: he is willing to sacrifice himself for the woman he loves.