So why does the bitcoin economy reward spending processing power? I guess our economy does too (quant finance)
Because you need some way to inject new coins into the system initially. Bitcoin chose to do this by allowing early users to "mine" the currency. The traditional approach is to have a central bank which does the minting and printing, and then the regular banks can borrow that money. Those banks then lend that money to their customers, possibly creating more virtual currency by fractional reserve banking. Bitcoin obvi…
Bitcoin isn't perfect. But we can test it, and if it breaks, we'll see quickly. Broken rep-net economies are like building markets on pyramid schemes: people have an incentive to pretend it still works until the damage is orders of magnitude larger than the economy proper.
And I encourage you to investigate what fractional reserve banking looked like in the days of specie-backed-currency. Banks still made loans and kept less than the entire value of their demand accounts on hand. It'll be weird, but there will be an M2 and an M1 in bitcoin, we aren't technically limited to an M0 money supply.