Just because something *can* be built, doesn't mean there's an incentive to live there. Example - you want a holiday home and have to choose between Dubai and Afghanistan. One has a stable (at least right now), clean and well run economy and attractive homes to buy, the other is torn apart by war. You *can* build a house in either, but Afghanistan right now is uninhabitable for most people. The Scottish highlands can have houses built on it - but who'd want to live there! Towns form where resources make it beneficial to live (shelter, water, commerce, etc.). Places that oppose that way of thinking are "uninhabitable" from the point of view that it will never make sense to have a settlement there.
If I sold my house here, I could goto the highlands and buy huge amounts of land and build a palatial house. What good would it do me? The area is uninhabitable unless you're a hermit.
a