I was thinking about something.
Until the mid 1980s, science fiction seemed to be largely dominated by political conservatives and libertarians. Sure, there were notable exceptions, but most of the big names wrote from a right-leaning political and economic perspective. Your Larry Nivens and Poul Andersons and Robert Heinleins were always throwing in dialogue about how the government is a plodding bureaucracy and how private enterprise would get the job done so much better. Writers would write fanciful future histories in which plucky capitalists did what the evil governments couldn't and privatized space travel, leading to a golden age of exploration and exploitation. They found ways to make profit and that drove an outward expansion. You'd also often get some commentary about how the environmentalists were stupid and nuclear power would save us. In sf disaster novels, there would usually be a group of rugged "survivalists" (read: gun nuts) who had their heads on straight while everyone else got killed. This was the reality of "hard sf" for decades.
Now things have changed. There are still plenty of libertarian writers doing their thing, but there are also a large number of moderate, liberal, and even socialist writers who have added a new dimension to the mix. Most come from the United Kingdom or Australia, but there are also some Americans. The active, vibrant core of hard and space sf is leaning to the left today.
I only mention this because I was reading a diatribe online about how there would never be any large-scale settlement of space simply because there are no real opportunities for profit there, at least not in the next few centuries. The logic goes that no government or private corporation is just going to send people to live up there without getting something back in return. The return from the investment isn't worth it. While libertarian sf writers argue differently, the interesting thing is that both of these ideas presuppose that the only motive for doing anything is profit. There is occasionally lip service to basic science and putting some of our eggs in another basket for when the asteroid/war strikes, but what is really needed to get people Out There is a chance to make some money. Because you know the conservative line: a growing economy is good for everyone.
Even if this were true, of course, I imagine the scenario would play out differently than the sf writers imagined. The plucky capitalists would stay at home in their robot-tended mansions while they sent out foreign labor to mine the asteroids and pay them just enough to have to keep mining while sending all of the profit back to Earth. Oh, and the medical insurance wouldn't pay their gene-resequencing bills when their bones deteriorated from microgravity. But I digress.
My idea is that if we accept that there are few profitable enterprises in space, that doesn't mean there will never be space settlement. It merely means there won't be space settlement by those who seek only profit: the capitalists. In a truly socialist society, the whole point is the good of all people. Assuming there are existential risks to humanity such as climate change, wars of annihilation, asteroid strikes, etc., it only makes sense that eventually you'd want to have people as decentralized as possible. If Earth doesn't make it, maybe Mars will. If the solar system doesn't make it, there's always Alpha Centauri. And if the venture doesn't make gobs of money for the people back home, so what?
In a real stretch of plausibility -- though in my opinion, a highly desirable stretch -- the bio-, info-, and nanotechnolgical revolutions yield a leisure economy in which nobody has to work and everyone had the resources to do essentially whatever they want. Making money is simply not a priority because it is unnecessary and social status is measured by your contributions to society rather than how many things you can buy. In this anarchosocialist world people would settle space simply for something novel to do, because everyone could afford it.
It's something to think more about.