A nuclear-proof bunker hidden beneath Greenland with air/water filter system will be 1000 times cheaper, and will promise a better survival chance in almost any scenario.

If humanity is wiped out on Earth, people in Mars are fucked anyway: they will be one depressurization accident from extinction.

If you don't think a space colony would have overengineered multiple redundancy against depressurization, you don't understand the psychological effect that vacuum being 6 inches away would have.

Assuming all the Martians live in a single pressurized structure.

Worst case scenario, what would that actually be like? A few hundred people who gave up their lives on earth to live in habitats on an inhospitable planet one day learn that the worst fear of the 20th century came true, and there's nobody left back home. It's just them, the only remaining sentient beings in the known universe, without 99% of the technology that got them where they are now.

How could they even begin to try to rebuild civilization when they can't even go outside without an apparatus that took thousands of years of science to produce? What is the speed divisor for advancement of a society marooned on a world it didn't evolve to live on?

I'm all for Mars colonization, but as a backup plan for Homo sapiens, it kind of sucks.

That's kind of a straw man. Musk envisions a city of a million. No one claims a few hundred is a viable back up.

Seveneves is a great novel that explore this idea:

https://www.goodreads.com/book/show/22816087-seveneves

Sounds like the concept for a great sci-fi novel.

> Not everything we do is for the monetary incentive.

It is when a private company is doing it.

It is when a public company is doing it. Privately-owned companies can do whatever the heck their owners want.

Public companies can also have whatever mission they want, subject to oversight from the owners.

Yes but the ownership is open to anyone, so it's a lot easier for activist investors to change the mission to a more profitable one. Musk is keeping SpaceX private specifically to keep this from happening.

But this is being driven primarily by one private individual.