I take it the point is to use the materials in space to first build something. Only once it's built will people actually come. The reason why our space programs are stuck in first gear is that we don't know how to build things in space from materials that are there. This will change soon, because many of the lessons of automated production techniques on Earth can be applied (with modifications) in space. The problem will be one of sourcing the raw materials from which to manufacture something useful. So that demand is perfectly predictable, and asteroid mining companies are now taking the baby steps they need to take to eventually satisfy that demand.
If you're wondering about what's worth making in space, there are many great ideas. Here is just one: A truly gigantic telescope mirror. It might actually be easy to do, because the factors that make mirror production on Earth so hard are not a problem in space. There is no need to worry about sagging, stress and all these other gravity-related issues. Space-built telescopes could get pretty darn big, The question is: what will they be made of? And the most plausible answer is: materials from asteroids. Like I said, that's just one example.
We want to create puppets that pull their own strings. - Ann Marion