And this has to do with Mars ... how?
The iron dust on Mars would create an infrastructure or a base process from which colonists would have something to strive for and achieve.
Human's haven't survived for millions of years just roaming around the planet hunting, eating, sleeping and reproducing.
Most humans however still live with the mentality of a caveman.
http://www.cnn.com/2013/12/10/tech/innovation/mars-one-plan/
The Mars One Plan in order to grow would need to have facilities that would actually produce a product. A product that could be used elsewhere in the Sol system as well as on Earth.