The thing is though that the ratings are given by humans. No algorithms here. Which means there are almost definitely going to be racial disparity. Even if we assume the ultimate ideal of nobody who uses uber is a racist, cognitive biases are a real thing and you're not going to be able to stamp them out in the large.
Algorithms do not create racism out of thin air, all the racial preferences are in the data. This didn't stop a bunch of projects from becoming crucified in the media recently.
I read an MIT study which said Uber pays women less than men, and they pay according to an algorithm that does not use sex as a factor. Would you have anticipated a lawsuit there?