The author does point out your Christmas light comparison but identifies a key distinction: for Christmas lights, the point is the colorful lighting for human e

The author does point out your Christmas light comparison but identifies a key distinction: for Christmas lights, the point is the colorful lighting for human enjoyment. That's the upside and the energy cost is the downside. Coming up with a lower-energy way to generate the same colorful lighting will save energy. For Bitcoin, the destruction of value is the point. The nature of proof-of-work is that you continuously expend more resources than a hypothetical attacker possibly could. If resources get cheaper or more abundant, you must burn more of them to compensate, because your attacker can too and you always have to outpace them. So Bitcoin incentivizes using an "expensive" amount of energy no matter how "cheap" energy gets.