I would like to take a moment to critique a certain strain of futurology.
There seems to be this thing where people imagine something that would look really cool, and predict that if we work hard on it for fifty years, we’ll be able to pull it off. And then fifty years later, when barely any work has been done on it at all, they start looking for someone to blame.
Missions to Mars. Lunar colonies. Giant floating solar power satellites. Undersea domes. Ten mile high arcologies. Humanoid robots.
Whereas real technology doesn’t advance by heading in the direction of something that looks cool, unless some government or tycoon is throwing lots of money in the direction of coolness. Real technology hill-climbs towards things that are useful and profitable.
Why haven’t we colonized space yet? For the same reason we haven’t colonized Antarctica. It’s very cold and not a lot of fun and if you go outside you die.