Look, don't compare Basquiat with any of the great masters of painting who have gone before. He was a young raw talent who came to represent the art scene of the 80s; a culture glorifying youth, money, excesses and ultimately self-destruction.
His paintings and drawings represented all that, but also black culture and history, as well as his own conflict with his identity. He also saw himself as representing the outcasts and rejects of society, and rejoiced in the fact that he, a sort of fraud, had made it in a 'white' world.
Do read art critic Robert Hughes short critique of his work and though you won't find the finer things about Basquiat that you are looking for, at least you will understand what made him tick and why his work is so popular
http://artchive.com/artchive/B/basquiat.html
and another point of view at http://www.johnseed.com/areply.html