In Coates concluding section, what is the meaning, the message, the metaphors, and the effectiveness of his message for you, Coates's son, and even the country?

Some readers might have anticipated a few inspirational words at the end of Coates’s letter to Samori; however, the author does not have any to proffer and ends his short but luminous book with a bleak image of driving through the ghettos of Chicago in the rain. What is very clear is that racial injustice and the Dream do not seem to be going away anytime soon, that believing one person can make a difference is a foolish idea, that black people will suffer from inequality and injustice for a very, very long time.