Dollars used to be backed by gold, and coins were minted out of silver. The dollar had the same value as the gold, but was easy to transport and anonymous. The coins had (and still have if they're pre-65) inherent value because they are precious metals, they're easy to transport for small amounts, and they're totally anonymous. There's nothing wrong with cash except the fact that it loses value, because it's not backed by precious metals.
Has anyone here even heard of Bretton Woods? Jeesh... That and the free market economy is the reason that the USA became the worlds superpower. We broke the Bretton Woods agreement and we no longer have a free market economy, which is why we're 16 trillion (100+ trillion when you include unfunded liabilities) in debt and on the verge of a currency collapse, which will lead to social unrest the likes of which the world has never seen.