It's worth pointing out that compared to other "useless" products of us humans like diamonds etc. bitcoin is rather ok environment wise. Green electricity goes up and down and can't be stored so bitcoin is a good way to create some "value" as those guys in the article are doing.
On the value side, "trust" is one of the most expensive commodities on earth. More "trust" creates more opportunities for business. Think if you could not trust a $1 bill to be exchangeable for some product. I think if you look at crypto as a way to increase trust in whatever area, you can start to see the value. Think of it in terms of Nash equilibrium, like a prisoner dilemma where you can "trust" your prison mate and both get more value out of collaboration.