A pile-up could easily cause a million dollars worth of damage. A measure that makes sure that the responsible businesses are serious about safety doesn't sound that unreasonable to me.
It's not for individual owners.
Seems to me that a company is going to need to sink many millions in to design, build, and test a truly road safe self driving car no? Even considering it as a hardware and software mod to an existing model.
Robot drivers are a new and unproved technology. After not too many years I'd expect that they will cause way fewer accidents per mile driven than human drivers.