[plusone]

My main objection to any of the monetary systems is the presence of a central bank. Why should a small committee of men get to decide short term interest rates, abd by default, the relative values of the world currencies?

[justshutupandtakeit]

Small groups of men have always decided those things or tried. After the Panic of 1907 the financeers realized that they were fortunate to have stopped the Panic before it did too much damage and without the presence of JP Morgan there would have been huge economic losses. This changed the view of many of them who had been adamently opposed to the call for a Central bank. After all that was the demand of the radicals from the West, the Populists and Grangers, not the banking class.

While the money center banks liked having all the power they realized that after Morgan was gone there would be no one who could protect the interests of the finacial system. No one with the means to stop the liquidity flows which could bankrupt all of them and millions more.

Your question is similiar to "why use antibiotics against disease?" Modern tools for modern economies.

BTW no one can control foreign exchange values. That was why fixed exchange rates were dropped and floating adopted. Even influencing these rates is difficult if not futile.