We live in an absolutely wonderful biome, at the bottom of a deep, steep well. Sending materials down the well might or might not make sense, depending on the needs of the people at the bottom, who will be the vast majority of humanity well into the foreseeable future. But for the people up there, asteroids could be a better source of mass and materials than sending things up from the bottom of the well.

Thinking about space habitats, or very-large-mass spacecraft made from asteroids, may seem fairly far-fetched, but it's fair game in opposition to the author's 'Never, Ever'.