What about the electronic power and human work that goes to operating banks? By that logic, the alternatives to Bitcoin are much more wasteful.
Edit: What I was trying to say, that maybe wasn't quite clear, is that Bitcoin mining isn't wasteful because it helps protect the integrity of the Bitcoin network. Other methods for holding and transferring money requires trusted third parties, who also "waste" (probably much more) energy, time and resources to operate.
Thats a fair point but why should I believe in bitcoin not another crypto ledger? The idea is fine, and the idea of a validatable record is great, but why should I support this one?
That's a complex topic with no clear answer. Philosophically, Bitcoin leaves much to be desired. But Bitcoin is the only realistic choice. The others (Litecoin, etc) just don't have enough momentum to be viable right now. Network effects make Bitcoin the only cryptocurrency with any short-term value.
However, regarding the philosophy: Bitcoin is a deflationary currency. That's a remarkable choice, because the prevailing economic wisdom is that inflation is a good thing because it keeps the money flowing rather than being hoarded. So most people probably wouldn't support Bitcoin's economic theory if given the choice.
Edit: What I was trying to say, that maybe wasn't quite clear, is that Bitcoin mining isn't wasteful because it helps protect the integrity of the Bitcoin network. Other methods for holding and transferring money requires trusted third parties, who also "waste" (probably much more) energy, time and resources to operate.