What's left out of this…
What's left out of this essay is world context. When GM came up with the idea of the Volt, gas prices were quite high. Recall that the 2007-2008 timeframe had the highest inflation adjusted gas prices we've seen since the 70s. We also had significant concern about climate change. It's not a coincidence that the Leaf, Tesla, Volt, and Prius plug-in were all about the same timeframe. They were all a development cycle after those high gas prices.
Why didn't Volt do well in Europe? Volkswagen's cheating scandal first made Europeans think that 'clean diesels' would be a better alternative than gas, then made Europeans skeptical about many big car companies. And, Europeans were used to diesels. So, Volt didn't do well there.
Finally, gas prices dropped significantly after the house bubble burst. So all of a sudden, there wasn't really a public desire for something like the Volt. Gas prices were fairly cheap from then until the early 2020s. Cheap gas encourages people to buy bigger vehicles. Had gas prices stayed higher, GM could have demanded a high enough premium for the Volt to keep it in production, and even expand the offerings with the Voltec system. But gas prices dropped instead.
If you're talking about motor vehicles, you can't really cover the topic properly if you don't talk about fuel prices at least a little.