Sure - the physical printing is just one of the many overheads of the monetary system. But the point is that these costs are small and, importantly, more-or-less constant. Whereas with Bitcoin the costs scale up (and inherently have to scale up) with the Bitcoin economy. Indeed, if we assume rational miners with accurate price predictions, then the amount wasted on mining Bitcoin always exactly equals the total value of bitcoins in circulation.
(So far we don't see this because the price is much higher now than it was when most of the coins in circulation were mined. On the other hand, if the Bitcoin price drops to e.g. $10, then the current expenditure on ASICs is going to look even more extravagantly wasteful).
> You're right that Bitcoin by nature includes a huge energy cost, but when you take the narrow view that it's simply being thrown away, it's both short-sighted that it ignores the theoretical possibility that its heat "waste" could be channeled into something economically desirable (e.g. steam to drive turbines)
Even if you find a way to use the heat, you're wasting the computational power that could be allocated to something more productive e.g. protein folding.
But even more importantly, and what I expected to be half the point of the article, the work put into validating the blockchain inherently has to be wasteful. If it isn't, the economic incentives against cheating no longer apply - you can just do a leveraged buyout of a huge turbine company, put their heat generators to work doing a 51% attack, and double-spend all your bitcoins.
Whenever someone comes up with a way to do hashing for half the energy, the Bitcoin network doesn't start using half as much energy - it starts doing twice as much hashing. The wastefulness is built-in and unavoidable.
