3 ms·

Perhaps because there is currently no supply.

• TeMPOraL 9y ago
  Exactly. This is a chicken-and-egg problem, and to break out of it, you need to address supply and demand simultaneously. Asteroid mining isn't happening in a vacuum (well, it is in a physical one, but not metaphorical). Fortunately, there are people working on using the mined material to manufacture things in space too; missions plans are being sketched around those capabilities.