We can assume that Chopin wrote this story for a white colleague. Not many people write stories about racial differences because white Americans today still subscribed to certain ideas or were afraid of being ostracized. It played a big part in why Desire's baby was so successful.
I think that in some cases the author's race plays a role in how his stories deal with race issues. You tend to trust people and listen to them when you can empathize. Chopin's criticism only served to attract the attention of people who looked like her. This was probably difficult for black people living at the time. Furthermore, when a person writes about the racial injustice he or she has suffered, people associated with the Learn to listen and talk about your experiences. Whether or not the author's race makes sense depends on the issue being addressed and the intended audience.