So the libertarian crowd is, once again, getting "serious" about building a city out in the ocean. I'm pretty sure they'll go bankrupt, too, just like their predecessors.
But it's inevitable that eventually they succeed; the idea is workable. Aircraft carriers are halfway there, although the pricetag of about $140,000,000 per person (granted, they're not -intended- as cities, so one intended as such should be cheaper), they're a bit pricy.
There are mansions (okay, one) which have fetched as much, and didn't carry the same tax benefits.
The ocean is the future of life on Earth. But it's not the future.
Terraforming isn't the future either, as popular as the idea is.
The future is space stations.
Not for refueling, or anything silly like that - for living in. The advantages are almost too numerous to list, but capital mobility would rank high if we did.
Anarchistic capitalism works in space in a way it does not work on earth. It's hard to drag your factory somewhere else if the country you're living in pisses you off - unless it's on a boat or in a spaceship. There's a reason the Russian train-based factories did so well when they were in a state of war.
Space does of course have an issue with scarcity of resources, particularly in the face of the bloom of a sentient species. And planets do have an advantage there. So I don't think they'll be entirely pointless, although I still think terraforming is right out.
But asteroids have the same advantages, and have transportation benefits to boot.