I guess this depends on the region, at least to some extent. In Northern Europe we've had these periods during fall/winter in recent years where it's cold, essentially dark, and (worst) no wind. It's not really feasible to store ≈multiple days of consumption for tens of millions of people.
In three of the four Swedish price regions I think we are essentially in a situation now where wind power is "worthless" and can't be built out any more, at least not without major changes to consumption patterns. When the wind is blowing there is such high production that prices go almost to 0, and the operators earn ish nothing, and when prices go up there is no wind so no-one can produce.
The pricing problem sounds like an artifact of how you've structured the market, not a fundamental obstacle to the profitability of intermittent power sources.
An alternative structure that would solve the problem would be for generation operators to buy put options for energy they expect to be able to produce, eliminating the risk of a price collapse. Consumers who want access to such intermittent energy would have to write those put options, which would be limited to particular times on particular days when they could use the energy. Having written the option, they would have to accept the generation operator's decision whether or not to exercise it. Utility-scale storage providers could write puts for low-demand times and buy puts for high-demand times, or they could write puts for low-demand times, write futures contracts for high-demand times, and make up the shortfall on the spot market. This might produce major changes in consumption patterns, but, more likely, would enable continued investment to minimize those changes.
For example this solution would be sufficient and have no blackouts/brownouts per year in 99% of historical data....
Extreme weather events are what is important and we do have the data.
Predicting how willing Swedes will be 10 years from now to buy extra jeans and install phase-change energy storage in their houses, however, that's beyond anybody's ability.
Tradeoffs are indeed inherent in any human effort, but actual market prices are an imperfect reflection reflection of those inherent tradeoffs, and can indeed be distorted by subsidies, externalities, etc. And often tradeoffs cannot really be reduced to a single scalar the way costs do—not everything can be traded off against everything else.
Yet that observation does not mean there aren't any real tradeoffs, or real tradeoffs that can be reduced to a single number.
Also, while this god's-eye viewpoint of the options available for collective action by humanity as a whole is important, for most of us it isn't useful tactical or even strategic information about the possible courses of action we could undertake to affect the world, much less our own lives. It's most useful if you're a billionaire, a Central Committee member, or a Civ player. For the rest of us, even Bilderbergers and the like, those subsidy-distorted costs and the failures of collective action that produce them are merely facts about the world; we cannot make them evaporate in a puff of logic by pointing out their irrationality.
But I think the bigger issue is the second bucket: the cost of turning heat into electricity seems to still be too high to compete with solar and wind, even if the heat were free. The article doesn't mention this at all, but I think it's the crucial issue. I don't understand why heat engines are still so expensive 250 years after James Watt, but they do seem to be. In January I came across https://www.eia.gov/analysis/studies/powerplants/capitalcost... which is an EIA-commissioned study of the capital cost of building different kinds of power plants, and I am hoping that studying it will give me the answer.
The article mentions the intermittency of wind and solar a few times as if it were a showstopper—as if no amount of solar and wind power generation capacity could be an adequate substitute for any amount of geothermal power, because you don't have solar power at night, for example. But actually that's just a question of how much it costs to store the energy until it's needed or transmit it from where it's still being produced. We have upper bounds on those storage costs from existing utility-scale storage facilities, and they already look pretty okay. We can expect that they will get cheaper over time.