Think about how many hoopties are already on the road with broken lights, bad alignment, bald tires, no ABS/ESP/TC, dangerous suspension geometry like semi trailing arms, no oil changes, etc. Why don’t we start handwringing about poor vehicle maintenance?
If it is a self-driving software update that the manufacturer could push but chooses not to (or could trivially port), I think it becomes much more difficult liability-wise and legally for them. I'm not saying that is the correct way, but I think it is how it would work in practice.
We do in some places. Where I live (Iowa) we don't - but most people take better care of their car than that so it is pointless. As a kid I remember parts of MN requiring inspection and a few years latter dropping it when they realized nearly every car was passing so there was no point (this was emissions only not safety). In Texas there are regular inspections - but if you go to border towns you see a lot of those poorly maintained cars on the road (despite the inspection) and so people see more need for them and they keep them.
