You can think that, but you are looking at the wrong side of the equation. The path down this thought process is being a bully -- "I don't want you to use electricity in that way". That is just your preference. Let the miners use power how they like, cleanly. Issue as many carbon taxes as you like to the producers if you feel it needs a finger on the scale. The miners don't tell you to stop wasting power on xmas trees.

Using energy is fine. Producing unclean energy is immoral. So is driving an internal combustion vehicle. We must get our power generation efficient and clean as possible.

Not understanding Bitcoin is backward thinking. Bitcoin is an incentive to move to clean power.

You can't stop it, you can't stop people mining it, you can't stop people using it. Complaining about the energy is like complaining about the moon. Nothing you say or do can make it go away. So get people to generate it cleanly.

Virtually all electricity has externalized environmental cost. Even electricity used to power a hospital. I agree this externality is immoral, not the hospital or PoW itself.

You don't see any ethical difference between powering a hospital versus thousands of video cards to solve a useless puzzle? None? Not even a little tiny bit?

What about the fact that those video cards use HUNDREDS of times more power than even a relatively busy hospital?

I see the ethical issue as being externalities from the electricity, not the hospital or puzzle.

But resources are not limitless.

Are you comparing utility of hospital with proof of waste?