Re: I'll start writing the disaster movie script now...
"If they can't have airtight security (hint: they can't) ..."
I downvoted because of one word, can't. It isn't that they can't, they can, it is that they won't. There is always some tiny saving in time or money that warrants, to that individual or contractor or investor, disabling security, bypassing air gaps, or saying to heck with it all and using the internet or some cheap IoT when something needs attention or upgrading.
"...in particular the ability to generate and remotely access document sets stretching from a transformer’s installation and commissioning tests right through to precise details of its last maintenance period before it fails,..."
We've had that ability for more than a generation and it almost never works. Sure sometimes it get set up, sometimes contractors can be forced to provide proper documentation but more often they will walk away from that last 10% payment because in the words of one contractor, "We never intended to supply that information, it wasn't part of our bid and it would cost far more than 10% to do it now."
Even when decent documentation is handed over Maintenance and Operations Departments are always the hardest hit when it comes to budgets. Most decide that RTF is the best course of action particularly when the equipment is newer. By the time they see the value in proper documentation it is too late. It cannot be recreated and capital expenses are always more exiting, easier to get and will have more support than operations and maintenance. For the majority wanting capital expense increases the more costs and failures Operation and Maintenance has the better.
"This is how we get to that future where a run-of-the-mill DDoS causes the collapse of civilization."
It does seem that way. The resistance to doing things properly is shocking. We have the potential, we have the capacity but we do not have the power to overcome money and lazy. Money and Lazy takes the path of least resistance and will breakdown impedance, cross gaps by induction, and it has the capacity to build up and jump over, by or through anything trying to be insulated from it's effects.
We we feel the minor discharges, we can see the corona it creates as it presses on undermining, degrading our attempts to contain it. It wants to flow freely with no concern for the damages it causes along the way. It is relentless. Struggling against such a force of nature seems doomed to failure.
Maybe it is best to let it win because if it doesn't win people forget why we bother.