Well, he's only one of many who talk about colonizing Mars. Trump is on board, in fact his bill s.442 makes it part of law that Nasa make plans for getting to Mars.
https://www.congress.gov/bill/115th-congress/senate-bill/442/
As for no air...did you know that the whole planet has ginormous sandstorms that will shred everything in its path!! You can't have a sand storm without air. Mars does have an atmosphere, although it is very thin and mostly CO2. But where that exists, there is a way to concentrate it and extract the oxygen.
So you're completely right - humans shall overcome and adapt. With a little air.

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Mostly CO2!!!!!! You mean that Mars already has global warming!!!!!!! Musk and his freak on a leash had better go there now and save that planet,before it's too late!!!!!!