THATS the disrupting part: You can rate your driver online. See https://www.uber.com/drivers You see the rating before you book a ride. This makes all the difference.
But aren't the ratings meaningless? I remember reading how Uber drivers were upset because a rating measurably below 5 out of 5 can get you fired. As long as that system prevails, a driver's rating won't tell you anything more than the fact that you found them on Uber did.
I think if you had the identity of the driver (both before and after the ride) a lot of drivers would not behave like criminals. Instead of fighting UBER these companies would do better if they put the client on the center stage and perhaps start their own rating-identity service.
The taxi registration and the time of the ride are as good as an identity for the purpose of identifying an individual driver if you chose to report the driver to the regulating authority...