Gold is traded almost exclusively for its liquidity and role as a value store, not for its intrinsic value. Currency traders don't use currency as a medium of exchange either.
What grandparent (almost certainly) means is that gold is a "monetary asset": although there are industrial, cosmetic and personal uses for gold, if people were not using gold as a store of economic value, its price would be much lower than it is.
More to the point, even if gold's industrial, cosmetic and personal uses completely disappeared, it would probably continue to be quite valuable because people would probably continue to use it as a place in which to "park" some of their savings.