Yes, but they coveted "free money", much like today's leisure class of welfare recipients, who are the quickest in our society to kill each other over $20. Gold was not something the miners earned through their own creativity or labor, it was just lying around in the ground, waiting to be dug up by who ever got there first with a pick and shovel, and a gun.
People who won't lift a finger to earn money are willing to expend great effort to loot and kill to get their hands on "free money". Rand addresses this exact situation near the end of the posted passage, when she writes of the race going to the most efficent at brutality.