With the caveat up front that I'm a huge idealist about space: I think humanity would greatly benefit from building large populations in space. Once the systems are in place then any power generation, industry, or agriculture done in space means less pollution here on earth. Solar energy is "free", asteroids are "free".
The setup isn't trivial, but in the long run I think it is best for everyone.
Colonizing space itself is also significantly more useful than colonizing planets, because you don't need a planet. Any star system in the universe is potentially habitable once we can work out a way of getting to them.
Yeah, only because we evolved on the surface of a moist rock doesn't have to mean we have to stay on the surface of such rocks for eternity. Planets are still valuable though, but mostly for disassembly. Pressure only a few km into earth's crust gets too high for any serious engineering projects and I doubt this will (fundamentally) change even with future technology. So most of the matter that makes up earth can't be accessed... unless we dismantle it. Asteroids are great but they only contain a subset of the matter of the solar system.
True, it would be nice to move elsewhere so that we can fulfill our DNA's desire to spread out. However, the Earth is the only rock we've ever found life on at all anywhere, including within our own solar system. Before we blithely plan for Earth's dismantlement, let's acknowledge that the problem of supporting life off-world is still a completely unsolved one. Even living in orbit is unsustainable, with astronauts spending time in the Space Station having cancer-like reactions to their time there. We are still very anchored to our little blue rock.
While CRISPR is great, it's no wonder drug. Immortality within a decade is a cool dream but has nothing to do with reality. Also, once you researched a drug, manufacturing it is usually cheap, so it would be a bad business decision from the drug maker to limit it to the ultra rich. But we are getting off topic. I agree with your general point though: with sufficient progresses we'll overcome the challenges of living in space. Of course, humans are built for earth, but it's no impossible challenge.
The rocket equation says that if you want to do anything besides sitting in one place, it's super expensive. Moving mass around requires throwing huge amounts of mass away.
My understanding is that it depends on how common/accessible water is in asteroids. If there is a source of water then it can be split into hydrogen and oxygen for "free" using solar power.
Throwing rockets' worth of water away seems wasteful, but if we have it then it isn't that expensive.
It's much easier to make an experiment for a human to do than to make a robot to do the same experiment. It's also cheaper for the institution doing the experiment to do so so we get more experiments done than we would otherwise and with less material waste.
That's a sunk cost fallacy. If they don't have anything important to do on said space station it's better to leave it empty and save the money for other projects. Mind you, I don't know if that's the case but I'm just pointing out that the station being expensive doesn't justify pouring even more money into it if you don't have a clear objective.
It maybe by sunk cost. But it's still lost value, at least based on design life and planned/committed-to experiments/ missions, which I believe are booked up through 2024.
And I'm not sure sunk cost fallacy applies, especially in the context of SpaceX / Dragon. Although it could definitely apply to SLS.
If you wanted to argue that extending the life beyond 2024 or whatever it is, then I would agree with you, sunk cost is irrelevant.
I tend to only apply the term to something incomplete with run-away costs to finish. Or if something changes (demand-side) that renders said product to become obsolete before completion. I'd argue neither applies to the space station. Political whimsy shouldn't be a factor.