I mean, we're not biologically adapted for the open ocean or winters above the arctic circle either. If all you're living in is your skin, then a Siberian winter will kill you in under 15 minutes. It takes a crazy amount of technology -- in terms of habitat-building and wearables -- to be able to survive in that environment. Yet humans were doing it 47,000 years ago.

So these kind of biological arguments really don't hold. We're not constrained by our biology. That ship has sailed, literal aeons ago. We're constrained by our technology, and in technological terms, relative to our evolutionary cradle, Inuit garb is about 80% of the way towards being a space suit. Doesn't mean that space is "easy". Just that "easy" isn't what we do.