Dutchman is a complex play open to wide interpretation. The general impression most audiences or readers would have is that its action is emblematic of the dysfunctional racial dynamic of America. It is not only the fact of oppression, but a sexualized form of it, that is represented by the character Lula. Clay is attracted to her but simultaneously repelled by her sinister manner and the knowledge that her intent is to destroy him.
Much of this scenario is deliberately exaggerated, even by the standards of the time when it was written. Baraka presents an extreme picture almost in the manner of a satire, but even so, the point is that reality is not much better than this. The title relates to the legend of the "flying Dutchman," a man condemned to be homeless until he finds a woman willing, through her love, to sacrifice herself for him. In this case, the legend takes an inverted form in which an African American man is similarly condemned without a home, but here, the woman who could presumably have been his salvation instead destroys him.
The symbolism is based partly upon the actual danger in the Jim Crow South to black men who even looked at a white woman. In Dutchman, the woman provokes the situation and then becomes the lyncher herself. Though Lula has instigated it, Clay finds himself implicitly charged "guilty" of the worst violation of the racist code, "miscegenation." No one in the subway car helps him, and in fact the other passengers are complicit, as they throw his body off the train. Even the African American conductor then "tips his hat" to Lula.
The message of the play is realistic but pessimistic as well. In some sense, Dutchman is a relic of its period, but the fact of continued race hatred and discrimination into our own time, despite the genuine progress that has been made in the past 50+ years, indicates that Baraka's message is still relevant today.