He said in the talk that this implies AI needs to be able to patch/deploy systems. The same thing needed to lock out humans.
It is very easy to imagine a rogue AI locking humans out of everything and having to do exactly what it says. Anything connected to a network is immediately compromised by it. There is no human communication beyond shouting range that isn’t AI approved.
The factories don’t work to make the medicines your family needs to survive unless you do what it says - in a situation like that people would kill for AI if it told them to.