It has been 38 years since Apollo 11 touched down on the Moon. Since then , humans returned 4 times and aborted a fifth landing. And then . . . humans have hung around low Earth orbit. In essence, we turned our back on that technology for something different right away. It was as if after Columbus returned, the Spanish stopped building ocean crossing vessels and concentrated on building really high tech galleys for use in cross Mediterranean trade. Finally, after all this time, NASA with the Orion spacecraft is finally building a craft capable of returning to the Moon or going to Mars.
Now maybe, interest in space flight is not libertarian -- after all, so far, most space utilization has been by governments. And there is truth to that -- I recognize the fact that for now at least, governments will take the lead. Yet it does not always have to be this way. The X Prize for one is showing that private initiative can jump start the space program. Further, there will come a time, soon I believe, when the technology will catch up with the cost. We can imagine a time when mining operations on the Moon or an asteroid suddenly become worth while. If Mars becomes an option on can imagine people setting out to terraform the planet, and building new societies.
It is said that much science fiction is libertarian. I believe that to have some truth. It may be too difficult to build a libertarian (or socialist, or theocratic) paradise on Earth. There are too many preconceived notions , structures and institutions. So if the Earth is unavailable, why not Mars?