Why Hoard a Barbarous Relic?

"Sell it all. Today."
--Jared Cohen (Margin Call)

This editorial raises a good point. Central banks around the world constantly smash gold as a 'barbarous relic.' Why, then, don't they just sell their gold?

If European central banks currently hold more than 10,000 tons of gold, they could sell their hoard and fund more than half of the bond purchases proposed by the ECB over the next 18 months. Why print money out of thin air with all those nasty consequences when you have a worthless rock with no utility sitting around that someone is willing to purchase from you for $1300/oz?

Because like you and I, central bankers know better than to part with their gold.

position in gold