You can sort of make a moral argument for Uber, maybe others in that one of the problems with the legacy taxi services is that they would refuse to provide rides to minorites, blacks in particular. With an artificially constrained supply of taxis, they could do this without penalty, possibly even profitably.
With Uber, sure an individial driver can decline a ride based on the destination and assumptions he makes about the passenger, but it's far more likely that someone will take the ride, since there are many more drivers. They also have less to fear with Uber since they don't carry cash or deal with cash payments, and there's some level of trackability/identifiability of the passenger in comparison to picking up a random person on a street hail.
With Uber, sure an individial driver can decline a ride based on the destination and assumptions he makes about the passenger, but it's far more likely that someone will take the ride, since there are many more drivers. They also have less to fear with Uber since they don't carry cash or deal with cash payments, and there's some level of trackability/identifiability of the passenger in comparison to picking up a random person on a street hail.