The first corridor, called Long Cellar, proved humans could create a livable environment under ground. The Original industry on the moon was soil production. This was done by carting a trailer load of topsoil from Earth, mixing it with equal parts moon dust and locally produced human body waste and troweling it into beds three centimeters deep, one meter wide with a half meter between, similar to the design by Bradberry. A few thousand imported Earth worms were added so the dead half meter between the beds would slowly become productive soil able to sustain the planting of useful seeds.
Seeds equal plants, plants equal oxygen. Oxygen equals life; so provide some. You won’t find any document which describes the first Luna migrants as useless people.
They’ll use every possible euphemism, but sift it to the fact we are talking people Earth was happy to lose.