Perhaps someone who did actually read what I wrote will realize that there are many, many things that do what Bitcoin does without the power usage of Bitcoin and perhaps seeks those as an alternative (like, PoS coins). And originally, the argument was "this is an environmental crisis," someone said "no it's not because of ferraris and backpacks," and I countered and said, yes, it's an issue. Why does anyone argue on an internet forum? I guess in the hopes of changing minds. I hope you would not find debate a waste of energy, at least not in a democratic form of governance.
> until people are confident that these other consensus mechanisms are at least as immune to attack as PoW is, they're unlikely to switch away from Bitcoin.
Yeah, that's the real meat of the argument, I suppose. We know PoW is at least difficult to attack. I am very happy that other consensus mechanisms are being explored though. I'm also not convinced existing non-PoW consensus mechanisms won't be as secure trust-wise as PoW.
I guess the overall point of this is that, yes, there's nothing I can do about people doing horribly wasteful things. But let's not pretend that bitcoin isn't horribly wasteful. Let's call a giraffe a giraffe. And maybe it's ok to be a giraffe if you're aware of the trade-offs, but it's certainly not a gazelle just because you're uncomfortable with the properties of giraffes.
The same could be said for people changing their behavior because you complain about it on a message board that the people in question don't even read. Nobody's going to stop using Bitcoin because you don't like it, so why bother?
That said, I think the cryptocurrency world is moving in that direction anyway. Most of the more exciting new cryptocurrencies use non-PoW consensus mechanisms, eg. IOTA = tangle, Ethereum Casper = PoS, EOS = DPoS, Stellar = SCP. And there's a strong economic incentive for that: when you reduce the cost of computation, you can use those computations for more applications, which drives adoption, which increases the value of peoples' cryptocurrencies. The challenge is that the fundamental benefit cryptocurrencies offer is computational trust, so until people are confident that these other consensus mechanisms are at least as immune to attack as PoW is, they're unlikely to switch away from Bitcoin.