The problem is payment. If you use the CC network, you're still getting tracked. Adding regular Bitcoin would not help much (most people would purchase them in a trackable way) but it'd vastly increase the difficulty in pushing for a switch.
The problem is the potential for dodgy drivers. No way in hell I'd get in a car that could be some random Joe Bloggs with no oversight. There has to be a central someone that says "this is one of our drivers" that can be held accountable.
