To be fair I guess even with a non-connected car that I have to update via USB, I could still download a malicious update. But at least we won't all get the malicious update pushed at once.
People vote with their wallets, and if the technology-savvy and privacy-conscious HN crowd is voting this way then...
However, if someday a zeroday is used to duke it out, a very angry, very unreasonable, not interested PR-Bla and Excuses crowd is going to assemble outside someones office tower. The someone will call the police, but the police will be busy, with the mess someones ECU peeping has made. The privat guards will do what private guards always do, if they see no good outcome for themselves and step aside. The escape helicopter pilot will have lost loved ones in the mess and take off. Someone is going to get shoved out the airlock, for all the other someones to see. That will have a interesting learning effect. Thus ended the lesson.
(or greater)
People can't really see it yet, partially due to a unwillingness to see the darker side of humanity, but a real cyber security expert is worth more than a cruise missile.
Planes, self-driving cars, swarms of aerial and underwater drones, fraud, propaganda, auto-targeting laser systems, surveillance, power generation and distribution, command and control interruption, machine learning + cyber warfare.
Who needs nuclear weapons when you have a zero day on a hundred million self-driving cars and you can get them to the nearest gas station or chemical plant going 300km/h?