Plus, there is the even more obvious reason - Burnham is a black woman and Amanda Grayson is a white woman. This show is intended as a prequel to TOS so there has to be consistency. If it isn't a direct prequel in the same universe, then they can change whatever they like.
No one suggested that she was Amanda's daughter.
Although she easily could be Amanda's biological daughter, and Sarek's step kid.
I have been on the receiving end of inequality and favouritism because I'm a black man, and neither one is pleasant. I do not care that the world has been, or mostly is, favoured towards white men, I have no desire to see a "diversity" that leads to more inequality. I, like many people, want to be treated fairy and to get what I earn. True diversity is everyone getting the same opportunities to advance, not because there is a quota or agenda.
We're back to the accusations of 'agenda' bullshit.
Joy.