It's a valid concern. Bitcoin could plausibly move to proof of stake at some point, though. And if it doesn't, there are still some PoS-based cryptocurrencies o

It's a valid concern. Bitcoin could plausibly move to proof of stake at some point, though. And if it doesn't, there are still some PoS-based cryptocurrencies out there that won't have that problem, so disliking Bitcoin doesn't necessarily imply one should dislike all cryptocurrencies. From what I can tell, that's only one of his many criticisms, if you read his blog. I'm sure he's sincere about all of the criticisms, and I agree with many of them in a general sense, but I don't agree with the conclusions or the (IMO) hyperbolization.