It's concerning that someone with a master's degree is comfortable using logical fallacies in their arguments.
Back to the topic:
1. Racism is the belief in the superiority or inferiority of a particular race.
In BWNO there is clearly the belief that white men, or more accurately, the white race is inferior to the black men. And in your fantasy what does the black man do with their superior positions? They use it to fuck. Not to improve the world in a policy manner. Not to improve the position of minorities or the downtrodden. Not to further emphasize equalization - they use it to fuck as many white women as possible.
That's some racist insane s/hit because even in your fantasy world, black men as just ignorant beasts. Just like white supremacists have done in the past.
You know one reason the Ku Klux Klan was founded? TO protect the 'virtue' of white women from freed slaves, whom they assumed could not control their impulses around those fine white specimens.
You know the most common stated reason for lynchings for the 100 years after slavery? Accusations of disrespected a white woman. Emmitt Till, a boy, lynched and murdered for whistling at a white woman and talking to her. Recently before she died, the old bitch admitted that she lied.
So what does your fantasy do? It takes that same mindset above, and makes it masturbatory material. That's why it's sick and racist.
2. BWNO is not racist because it involves consenting adults engaged in roleplay.
No. IR play, involves consenting adults. Your racist fantasy involves a lot lot more.
Hope clears it up for you.