Not to mention the huge revenue shortfall when parking meters and public parking lots are no longer used. You tell your car, orbit the building for a while I'll be about 40 minutes.
This does mean we don't need the huge car parks around places of interest as everyone can be dropped off and picked up at the front door.
(And when the car is going to self park, it can use speeds and routes that avoid adding congestion to the people trying to get somewhere.)
The cars won't orbit though, they will go park themselves or pick up someone else for an errand.
The exception to this will be autonomous taxis, of course.
There is a difference between what "is" and how the system responds to what "is". In this case I don't doubt for a moment that drivers of self driving cars would use this technique to economic advantage, and yes if it got too bad it would invoke a response (much like the $5 parking meters with credit card readers in them was a response to cars in general).
(Too bad it'll probably be a while before robot cars can legally operate without a human in the driver's seat and paying attention, though)