The previous essay is also good, and explains why most plants are green and not purple. (Purple plants absorb the most light in the green wavelengths, which is the most energy-dense band. Apparently purple was once the fashion.)

That essay shows that the author is arguing from economic models and the assumptions behind them. Since we can't predict what every individual will do, I think using models is the best way we have to understand and predict behavior, but the predictions won't be perfectly accurate in the real world. For example, he says

Whatever “it” is, if it creates $100 worth of value, but costs <$100, everyone will be doing it as fast as possible.

If everyone behaves like homo economicus, that is. In practice, it is possible to extract meaningful profit from opportunities, because you don't have to compete with an infinite number of infinitely adaptable agents behaving perfectly rationally. Succeeding in business usually takes a lot of work, but an important factor is identifying an opportunity that is underexploited.

With Bitcoin, the assumptions behind the models probably hold up better than usual. Location is irrelevant, so far more agents can consider participating as miners. Value is mostly ascertained in terms of exchange for fiat currency, eliminating many complications (value of labor depends on getting a job, value of a banana depends on season and flavor). You still have to do the work of exchanging them, so I would not pay $99.99 for $100 worth of bitcoin if I intended to change them back to dollars. But for bitcoin more than many goods, we can suppose that miners will have to spend close to $100 to get the amount of bitcoin they can exchange for $100. (In other words, arbitrage is fairly easy, so there isn't very much to gain from arbitrage.)

This essay appears to be a critisism of bitcoin alternatives that are said to be less "wasteful." (Presumably the perceived waste is the millions of dollars spent daily on electricity for mining.)

By my understanding, bitcoins are awarded to miners who solve a math problem. The math problem is difficult and the difficulty is increased in a planned way to control the rate at which new bitcoins are awarded. Other than as a way to get bitcoins, solving the math problem is absolutely useless. Our understanding of the world is not improved, mathematics does not move forward. It is very much like guessing a random, computer-generated password. Once you have done it, the only thing you learned is "this was the password," and it doesn't help you guess future passwords.

Apparently some bitcoin variants have appeared which have introduced variations on the "guess the password" game. The author argues that there is no way to avoid "wasting" (i.e. consuming) the resources that are used to mine for bitcoins now. If you make an adjustment that reduces costs somehow or provides some extra value to somebody, it will increase the incentive to mine just enough to balance that adjustment.

I think this would be true according to theory for most goods, and bitcoin is only singled out because it behaves more like the textbook predicts than most other goods.