Sure, but "there are racial disparities in this domain, and therefore in the data" and "there aren't racial disparities in this domain, but there are in the data" are very different problems. The latter is the topic of discussion and is much less ambiguous than the former.
There's also "there are no racial disparities in the training data, but the system still shows a response with racial disparity."
ML has problems with all of these at times. The particular case here with the Obama picture is a particularly vivid illustration of one that can be used to bring attention to the overall problems.
