It would make more sense to colonize Antarctica than Mars. There is literally no point in sending anyone to Mars.
Eh... not as bad as you might think.
Economically, and in terms of raw elements, Asteroids are better, but Mars has some stuff going for it.
The thin 1% atmosphere is better than vacuum in some ways. You can aerobrake and use parachutes there for part of your landing, saving fuel. Doing it for "free", every pound of fuel you save is a pound of something else you can take there, or one pound easier getting there for the same payload.
Further from the sun, so CME radiation is lessened just by the factor of distance.
The thin 1% atmosphere actually does provide some radiation shielding.
-60 to -200 below is still way nicer than Venus at 900 degrees and 90x sea level pressure.
The 1/3rd gravity is presumably only half as bad for bones/muscles for g-depletion than long term stays on the moon's 1/6th gravity. And with gravity you can do "I've at least got somewhere to stand and my tools and feet will stay put..." type of construction with wheeled and tracked vehicles and power equipment. How to mine asteroids without even being able to use your own weight to hold you down against digging and drilling is going to be a bitch. The fact that many/most asteroids aren't even solid, but rubble and dust makes this worse.
Mars still has more volatiles, ice/water, carbon dioxide, oxygen etc. than the Moon does. And with the thinner atmosphere and lower gravity, lifting them off of Mars is cheaper too. Say there's some big space-station just in Earth-Moon space someday. It may work out that shipping the stuff to build it that the Moon is lacking would be cheaper from Mars. Especially for stuff like water, ice, iron etc. that can wait, and won't go bad if it lazily makes it's way back here over a few years.
And carbon is important too. The moon does not have a lot of carbon, or at least carbon bound up in things that won't take a lot of energy to release it. The Moon has lots of Oxygen in it's rocks, but Oxygen is pretty much in all the Mars rocks too, and again, more chemically available for cheaper. It's in the rust, that's why everything is red there... On the Moon, there's some easier minerals, but a lot of the O2 would be gotten by having to melt down quartz or whatever. Asteroids, especially icy ones may well have way more volatiles and carbon than Mars pound for pound, but they still have the "catch a greased pig" problem with the almost zero gravity listed above. Ceres might be the exception, but it's gravity is still damn low. And it's halfway again to Jupiter further out than Mars is.
And yes, I agree the economic use-cases for space aren't very solid... yet. It may not even really happen until there's enough people and industry/need out there for it to be self-sustaining and shipping every last thing from Earth becomes too expensive. It's a leap of faith to assume they'll someday outweigh just doing things smarter/better and more efficiently on Earth, including Antarctica... but that's the one big problem. All these things are "
on Earth". Most of us are AGW/MMGW doubters-skeptics, but other stuff, asteroids/comets, AI Apocalypse, a genetic engineering/nanotech apocalypse, accidental or on purpose, Yellowstone supervolcano, a natural super-flu that wipes out humanity below replacement ability, or the ability to get society or technology going again for a few centuries... the odds of at least
one of these, or something else "bad" happening that we haven't even thought of yet, within the span of recorded history, say 5000 years in the next 5000 years starts approaching 100%.
If we don't get a viable independent population off of Earth, we
will go extinct. And obviously, having a robust space-based civilization in our Solar System actually means we can prevent some of the extinction events from even happening in the first place.
If someone has the attitude of "Meh... if we go extinct, we go extinct, we're not special." All I have to say to that is "you first".
