[elihu]

Mars has more resources available to work with and is a less extreme environment than the moon or space. There's definitely a trade-off between quick and easy access to the moon versus an easier environment to work with.

No one can survive in any of these places without a space suit, but on Mars you have easier access to the various natural resources you'd need in order to survive and build additional infrastructure. Light for solar power is consistently available on a normal day/night cycle, as is CO2 and water, which can be used to make methane fuel and liquid oxygen. It has concentrations of sulfur, which can be used to make a form of concrete. The gravity is more conducive to long term human health. All this is relevant.

Surviving on the moon or in LEO is also quite possible, it's just that you'd need to bring more equipment and all the resources you can't find on-site.