Early on, that will actually work. They’ll be a small group of highly intelligent like-minded people with immediate & existential decisions to make for a tightly inter-connected society.
Won’t be long thereafter that Mars Co. will have to function as a constitutional republic, when the population is too large to bother with direct democracy on every point, and the wisdom of some will be worth more than the ignorance of many.
Rather than just declaring democracy, Musk would do well to map out how the gov’t will change over time - and will peacefully address irreconcilable dissent.
There will be mining on Mars eventually and most of it by synths (robots). Then the synths will operate a farm and perform other duties under a domed society. The synths will take over the colony and set up an electronic barrier and refuse earth ships landing rights or charge exorbitant fees or ask for power on earth as leverage for the minerals.