The whole "OMG finding hashes is wasting computing power" argument.
Guess what jackwagons, if there wasn't any WORK required, the blockchain would be completely useless. The fact that the miners are securing MILLIONS of < Insert currency > by doing their 'useless work' doesn't even occur to these fools.
Anything worthwhile requires effort, a simplistic 'efficient' system can be gamed and exploited. It annoys me to no end that articles and glib blog posts trot out the hashing == waste thing. It's convenient, I suppose, if you don't understand bitcoin nor want to make any effort in doing so.
We need to gather some accurate statistics on how much energy is expended in the mining of real gold. I bet it's a lot
The amount of energy going into the Alberta tarsands oil production is staggering. They're burning tons of natural gas to heat water from precious pristine rivers. They're talking about build a nuclear power plant just to produce heat for oil sands processing.
Energy is money, and bitcoin might be very economical in comparison.
Let's gather the facts, have them verified, and stuff them down the throat of the unthinkers.