Every settlement in human history was shaped less by its destination than by who was permitted to found it, and on whose authority.
This is the question the current conversation most reliably avoids, and it is the one with the worst historical record. The pattern of terrestrial colonisation is consistent enough to be predictive: a venture financed by concentrated capital, justified by destiny, staffed by the useful, governed by the funder, and accountable to no one who bears its costs.
Nothing about leaving Earth’s gravity well changes that pattern. If anything the conditions worsen it: extreme dependence on a single supply chain, a population that cannot exit, and a communications delay that makes external oversight structurally impossible. A Mars settlement is, by construction, the most captive arrangement ever designed.
Whoever writes the rules before departure writes them permanently, because there will be no mechanism to revise them from outside. That is an argument for doing the philosophical work now, while it is still cheap, and while the people it will govern can still participate in it.