Months on a space station the human body starts losing its grip, the eyeballs, the joints, all sorts of places. Ends up earthly gravity is a great need of the human body. Just look at the seasons on earth. A little tilt gives such variation. The earth is immaculately placed. It is just the right distance from the Sun. The moon gives earth much-needed stability.
The surface of Mars is more hostile, physically speaking, than the deep ocean, and I don’t see Elon colonizing the deep ocean. And the deep ocean is hostile. Start with the immense pressure. Building ocean cities on earth, say in the South China Sea, is less challenging than colonizing Mars, and we are not yet into ocean cities.
And there is loneliness. Long months on a spaceship can be more injurious to health than smoking. I get the impression Elon could use a few doses of Human Biology 101 and Human Psychology 101.
The Blockchain does not take you to Mars, it takes you to the masses right here on earth. We are in the Goldilocks zone, yo. There is no Plan B. Save the earth.