[nas]

I hate the term "mining" for that reason. It is not like mining gold. I would have preferred if they called it "digital notary service". That's what the miners are doing. They are notarizing transactions so people can agree on the ledger and so that double-spends cannot happen. Early in the life of the system, the notary service is subsidized by inflation. Later (after many halving of rewards), they will be compensated with transaction fees.

If someone can devise a way to perform the notary service without proof-of-work, I'm pretty sure Bitcoin will move to it. Right now, no other system has been shown to actually work. Proof-of-stake systems are in the works but, as far as I know, none of them are considered trustworthy at this point.

Edit: I would like to also say that I'm sympathetic to the opinion that Bitcoin mining is too wasteful of resources (i.e. electricity). I think the system is perhaps flawed in terms of the connection between Bitcoin price and the economic drivers of difficulty. When the price is high, the mining rewards are such that there is huge pressure to increase mining costs. Do we actually need that level of security? OTOH, hard to blame Satoshi for the design since it is hard to foresee how quickly the system gets adopted.