Bruce better start believing then, since the Gobi Desert is inhabited and the Oyu Tolgoi copper & gold smack dab in the middle of it powers over one third of Mongolia's GDP.
While it's true the Gobi desert has been sparsely populated for ages, saying that a mine is a colony is like saying an offshore oil platform is a colony.
A self-sustaining Mars colony needs enough people that there is spare capacity to raise children and educate them to the point that they can maintain the systems themselves. That's going to be, what, 100K+ people? 1M+ people? 10M+?
https://en.wikipedia.org/wiki/Oyu_Tolgoi_mine