So, the major issue with settling moon is resource availability: water (!), carbon, fertile soil, and energy.
On the moon you have none of that. Maybe, with a lot of luck, you find water somewhere. Then you need carbon, energy during the long moon nights, and soil that isn’t razor sharp particles.
On Mars, you have all of them: low concentrations of water in the atmosphere, carbon from carbon dioxide in the atmosphere, soil that isn’t razor sharp (thanks to erosion), and the nights are short enough that you can make it through them.
Debian for the Transbians (trans lesbians).