Agreed. However, the tech is rapidly maturing. There are several companies that offer 3rd party solutions for autonomous cars (i.e. MobileEye). They don't have to reinvent the wheel. They just need to get in on the ramp up so that when these stuff hits big time in the next 5 yrs they are well positioned to take care of it.
Alternatively, here are some interesting use cases...
1) Mixed fleet of autonomous and driven cars. Autonomy mode is only used to "bring" the car to you, but you must drive it to your destination. Then autonomy mode is used to "bring" the car to the next customer. It's like an instant, on demand, just for as long as you need it, rental car.
2) Limit autonomous rides to major routes along major roadways. These roadways will be well mapped out. Will be under constant surveillance for changes that could affect the autonomy. Possibly will have beacons installed along the way for hyper accurate position triangulation without the phase errors that GPS has.