The point is valid but this paper makes a bit of a time jump. We are not going to swap over from meat bags to microchips overnight. Cars will automate more functions over time. Cruise control became adaptive cruise control became autopilot. Reversing sensors became reversing cameras became surround cameras and self parking. In the medium term, even self driving capable cars will allow meat bag control, so the pedestrian has to risk the fact that the car may not be under AI control.
In reality, many cars today come with autonomous braking systems that could equally be pranked by chicken players. In another few years, that'll be every car from energy level up (probably will become part of the highway codes)
I'm a bit more optimistic than the paper anyhow.