I don't think this is something we fix, it's something we evolve and move on from. My impression was the only real future relative to a grid security crisis is in storage and renewables, with more localized generation. The alternative is basically nationalization.
I work in ICS for a wind company and this is shocking...even when you're working with other entities (regional, ISO, etc) in the same industry. Some entities don't even bother reading the details of NERC CIP V and completely bans you from even accessing their meters.
(Perhaps an occasional electrical blackout is good for a society in the same way an occasional fast is good for a human body).
The pentester got in, got to the correct controls and "failed" because the UI bugged out. It was rather funny to see the journalist/moderator be relieved, while the rep from the energy company and the security specialist both clearly knew that that was sheer luck and with a little more time the pentester could've gotten around the bug too.
Edit after checking the story again: The hacker thought he found the main control but was wrong and only turned the lights off in a tiny side street. So it did work and the "bug"/"luck" was that the UI was so confusing that the attacker got it wrong :D
This actually surprises me because I would intuit that people would be drawn to hysterics about massive grid failures. Look at what happened in New York City.
And there are many smaller things that get even less consideration. Like the Tesla Powerwall Hack 
Either some big incident is going to happen that makes us shape up real quick, or we’re going to have a little foresight and proactively upgrade the security of our critical infrastructure.
All power companies have end to end land access and already have scada etc physical links between all switchyards and can run their own microwave links where necessary so no need for ANY infrustructure to be accecible from the internet.
Its lazy cheap decision making.
You don't even need to do that as it happens organically. At my company, we had a comms outage to a wind farm for several days (and the outage was wide enough where even surrounding wind farms outside of my company were affected) and just two days ago, the LEC (Frontier) discovered a bird build a nest in one of the junction boxes which links up to all the plants. All of this happened in a span of five days or so.
The cybersquirrels have won.
I remember reading a commentary on the cybersquirrel1 site introducing this "event" along the lines of: "In one of our more unusual operations..."
What this site beautifully illustrates is the entirely lax physical security of power substations and other distribution infrastructure that hundreds or thousands of households depend on. A distributed, coordinated human effort could destroy enough infrastructure to cause multiple days if not weeks of no electricity for a significant area. The kind of damage that would require the infrastructure to need rebuilding from scratch, or close to it.