Mars is the only place beyond Earth that:

- We can plausibly reach without "new physics"
- We can reliably find hydrothermally-processed ore without "new geology".
- Our technological toolkit can "just work", for mining and manufacturing.

The wind speed is a lol, you know that. Perchlorates are a nuisance that solves itself quickly in the presence of water and organic materials. The radiation is attenuated by that thin atmosphere, and more by a roof of dirt. 

Water gonna be a problem though, and the atmosphere is just a little too thin for respirator+spandex.

But Mars' unique value proposition is the absence of f--cking humans.

Ain't no tax man 225 million kilometers into space. Nobody dropping cluster munitions on crowded beaches there either. And six-year-old kids can die of a lot of things on Mars, but probably won't be machine gunned by a tank crew that's had her cornered like a mouse for an hour.

I wish Elon all the best in colonising Mars, and I agree with him that our species NGMI if we have to sharehouse with maniacs on this one rock. 

 I think I’ll stay here, love earth too much. 

 I guess I'm a contrarian when I say:   Even after a massive global thermonuclear war, Earth will still be FAR more habitable than Mars even with tax men and cluster munitions or tank crews.  If you have to dig underground on Mars, you could dig underground on Earth and probably avoid all the tax men, cluster munitions and tank crews just as well.  If half as much money was poured into surviving post-holocaust perhaps underground on Earth, I think that would be money better spent.