> I suspect a lot of people didn't realize how much power was being used for bitcoin.
And another thing which changed is that, every time the price of Bitcoin increases, it can (and will) use more power (the amount of power a Bitcoin miner uses is limited by how much power it can buy with the mining rewards, because if it used more power than that, it would be mining at a loss). There's a lot of difference between when one Bitcoin was USD 1, when it was USD 4000, and now that it's over USD 50000. Someone who was OK with how much power the Bitcoin network used back when the per-block mining reward was around USD 50, might not be OK with how much power the Bitcoin network uses now that the per-block mining reward is over USD 325000.
And another thing which changed is that, every time the price of Bitcoin increases, it can (and will) use more power (the amount of power a Bitcoin miner uses is limited by how much power it can buy with the mining rewards, because if it used more power than that, it would be mining at a loss). There's a lot of difference between when one Bitcoin was USD 1, when it was USD 4000, and now that it's over USD 50000. Someone who was OK with how much power the Bitcoin network used back when the per-block mining reward was around USD 50, might not be OK with how much power the Bitcoin network uses now that the per-block mining reward is over USD 325000.