I believe there can be a number of reasons, but probably the most common might be proximity to whiteness.(?). When Black folks are lauded for their intellectual prowess they are often given the unicorn treatment and positioned among curious white folks who end up enamored with their “brilliant Black mind.” I’m sure that in many cases, the white suitors turned lovers often present pathways for Black intellectuals that they may not have had access to, thus deepening their affinity, but idk 🤷🏾‍♂️