Arthur C. Clarke depicted the 'beanstock' type of space elevator in his novel "The Fountains of Paradise", which I can't remember what it was about.... hmmm. Time to read it again. There's lots of other books with the same type of thing. It's an old idea. Sometimes I think people 3000 years ago were able to conceive of the things we take for granted today, but couldn't achieve the necessary societal conditions to make it all happen. For example 'the tower of babel'.... regardless of whether it was a real attempt at a tall building, or just a parable, it shows the imagination that people had even 5000 years ago. In retrospect we wonder why they would build such a thing? Today we know that skyscrapers and apartment highrises allow high population densities and efficient commerce. Five thousand years ago they didn't have commerce on a scale to justify skyscrapers, nor the techniques to build them. But mostly it was probably the means & methods of prehistoric commerce. They simply didn't make the connection.

What is the true benefit of a space elevator? Surely not merely facilitating huge on-orbit construction efforts. What else? Who knows! We may end up building a space elevator for a completely unexpected reason. Currently there are not enough people in space to identify a market, or conduct any meaningful business. All commerce takes place on Earth's surface, and so far communications satellites are the only identifiable space-based "facilitator" of commerce (just like sky scrapers facilitate more efficient economy through low transportation costs). But what would justify building a space elevator?

Once we have a space elevator all kinds of things will become possible that weren't possible before. We may identify literally millions of scientific experiements that we could perform, millions of new technologies. Throughout all this invention is a kind of natural selection -- the thing that makes it all worthwhile hopefully drops out of the mass of permutations, and makes itself known.

However consider that it would take 50-100 years to build a space elevator. That is a lot of investment for an unknown payoff. I am thinking that construction of orbiting habitats isn't good enough reason.

We just haven't made the necessary connections yet.