[Chris Talk]

And who was it that taught humans to value it, enslaving them to work in their mines?

[Chris Talk]

Not that they would value our LIVES higher than cattle, but the cattle taste better, are bigger and meatier, have fewer communicable diseases, are easier to catch and slaughter, and are furthermore required by the aliens for their nutrition.

[Modernman]

And who was it that taught humans to value it, enslaving them to work in their mines?

Gold is valued by humans becuase we find it aesthetically pleasing, it is rare and it is easy to work with and turn into jewelry. The only way an advanced species would consider gold to be as valuable is if they saw the world the same way we do (rather tham say, in the infrared spectrum, or through sound or smell) and had the same sense of aesthetics (shiny=pretty).

And, again, slave labor is a pain. If they loved gold so much, it would be much simpler for them to send robotic miners and processors to the asteroids or to an uninhabited moon and get their gold from there. Using primitive humans to mine it is an extremely innefficent way to get gold.