>there are no private property rights on Mars
Not until someone gets there who can hold his property, no.
> it seems like a low goal for someone who wants to develop outer space.
It is *a* goal. There is no end-goal.
Complaints about various locations in space always amuse me. The Marsoids who go ape at the suggestion of lunar missions, for instance.
Nobody in the private sector is going to go to Mars without preexisting private property rights. There is no economic incentive to doing so. The public sector may send an expedition, but they won't set up a permanent colony except an Antarctica type science station.