Launch costs are coming way down. Once we get enough people into space to get industry going this will be great. Give adventureous people something to do and not destroy our planet. Asteriods are airless lumps of rock and metal just hanging around.
We launch a few rockets to bring starter ewuipment and from then on everything gets mined from NEAs (Near Earth Asteroids) or the moon. Then no more rocket launches needed except to refresh crew as we already do with ISS.