We can't breathe oxidized iron or carbon dioxide. We'd need to convert it into breathable oxygen and the mechanism would have to be foolproof and have redundancies. And that still leaves plenty of other problems.
But my main point was to everyone in this thread criticizing the authors for being pessimists. This isn't just naysaying or complaining. The authors are pointing out all of the necessary research we still have to do before a space colony can be feasible.
The point of books like this is to underline areas where we're still woefully ignorant to guide future study. This isn't just complaining. It's taking stock of what we still need to learn.
You don’t think all the scientists and engineers working around the world on this problem aren’t aware of the potentially fatal issues?
Scientists catalog what we know and don't know and try to chip away at the list of things we don't know. The whole point of the book and this article is that there is way more stuff we don't know than we realize and most discussion of space colonization tends to forget the parts we don't know.
The article even pointed out some very showstopping issues:
No one has been conceived in low gravity, no fetuses have developed in low gravity, so we simply don’t know if there is a problem. Astronauts experience bone and muscle loss and no one knows how that plays out long term
I was shocked to learn that no one really knows how to construct a long-term habitable settlement for either the Moon or Mars. Yes, there are lots of hand-wavy ideas about lava tubes and regolith shielding. But the details are just… not there.
For instance, supposedly space will end scarcity… and yet, any habitat in space will naturally have only a single source of food, water, and, even more urgent, oxygen, creating (perhaps artificial) scarcity.
Space colonization may happen, but it's incredibly doubtful that it'll happen in our lifetimes.
In the first link you provided, NASA themselves say we'd need a 25,000 watt power plant to scale that up. That's not trivial.
Again, what the authors are pointing out is that space colonization is probably scientifically possible, but will take a lot of research and then investment. MOXIE is a great tech demo, but its not a solution by itself.