The overarching goal is to have a "backup" of humanity so to speak. Having some of society living on Mars so that if something were to happen to Earth, humanity wouldn't cease to exist. Settling Antarctica doesn't solve that problem.
I'm a huge Musk fan and would love to see us settle mars.
But. Really. What's the threat model here?
Mars is meant to be a backup of humanity. OK. Against what threat? We can think of many, but a self-isolating base in the Antarctic would survive nearly all of them with better conditions than a Mars base.
Nuclear armageddon? Not much fallout over Antarctica and OK, you can't go outside of a while. Still better than Mars where you can't go outside ever.
Runaway global warming? The ice will melt but at a slow pace that leaves plenty of time for adaptation, the climate will become more hospitable at the poles rather than less, and at least you will have lots of fresh water. Unlike, say, on Mars.
Global pandemic? An Antarctic base can self isolate, no problem. Just lock the doors and let anyone who tries to reach you freeze to death. A serious Mars base would need some sort of border control policy too, if Musk had made it cheap to get there.
Massive asteroid strike? I guess it'd wreck the atmosphere but ... well, then you're no worse off than on Mars which doesn't have one to begin with. And you're much more likely to get nuked by a 'roid on Mars where there's no atmosphere to burn it up.
I dunno man. I'm trying to think of a problem that a serious Antarctic city couldn't solve and coming up blank. Short of Earth getting sucked into a black hole or something, what scenario is survivable on Mars that isn't at the poles?
Antarctic city is good. I like underwater cities personally.
A decent depth of water is very good protection against an awful lot of stuff, including almost anything Mars would be good for, and if you still love space, any technology we build to live deep in the ocean can probably be reused on Europa.
It's also, to bring it back to the 'iteration' discussion way way easier to iterate building underwater cities than building habitats on Mars.
Yeah, exactly. Problem is 'underwater base' is probably too easy to build. Within a few years you'd be asking people to actually live there and then ... well good luck motivating employees with that vision!
About the only thing that'd make it harder to survive on Earth than on Mars is a planetoid-sized impactor. For anything else a few hardened, isolated bunkers would be a hell of a lot cheaper than colonizing Mars, at least as effective at improving human survivability, and we could start building them today.
Of course I'm rooting for the Martian stuff because it's cool and may be accidentally useful (SpaceX already has been, really) and beats the fuck out of finding new ways to sell crap to people and the other garbage lots of other prominent companies do, but the goal isn't valuable per se, in my opinion.
