If she made this decision herself, cool. I have no problem with lighter black people playing African roles because there are lighter Africans. I do have a problem with someone who is NOT black playing the role of a black woman. She's biracial, so I can appreciate her choosing not to out of respect. But she didnt say she didnt take it because she's biracial, she said she didnt take it because shes lightskin and thats a bit dumb since African heritage has a huge spectrum of color. I also dont believe she "passed it up". More kikely that they passed her up. Why else would her agent say
"Do you want to keep fighting for this?". They were fighting for the casting.
Rest assured though that if she got the role, she wouldve gotten bashed.