So the black nationalism in everyone must always defend the way they are victimized as a race, and one way to fight against that is simply to have more African Americans. people who all feel the same way to help provide a sense of support for whatever needs to change. Of course, biology and science teach us that the only way to have more people is through reproduction, which is a bit complicated now, but used to be directly through sexual intercourse between men and women. Back when slavery was prevalent, the idea was to keep your family line safe and intact, so the only thing they knew or were allowed to do was reproduce so those children could grow up on the plantation and eventually work like their parents did. So this problem of black nationalism and homosexuality is nothing close to recent history and goes back further than some recorded events. You can see that by the way Alike's parents act and who they interact with, they probably both support the nationalist view and dream of seeing their two children grow up, marry a nice young black man, and raise nice black children. . This, combined with how her mother claims to be rooted in her faith, can be seen as very problematic for Alike. We see this later in the film that her mother essentially disowns her and won't forgive her for becoming who she currently is, saying she would pray for her. Favoring this increase in one's nationalism as well as one's religion instead of loving others regardless of their