I've noticed this too, and it's not just small blogs or comments either, in recent weeks I've noticed a few articles about the energy requirements of Bitcoin mining cropping up in the New Scientist, The Guardian, and the BBC.
https://www.newscientist.com/article/mg23631503-300-bitcoin-what-a-waste-of-resources/
https://www.theguardian.com/commentisfree/2017/nov/26/trouble-with-bitcoin-big-data-huge-energy-bill
https://www.theguardian.com/technology/2017/nov/27/bitcoin-mining-consumes-electricity-ireland