And I thought successful self supporting - profitable - space enterprises using real technologies are unrealistic and undeserving of the excessive optimism and hype; but with imaginary technologies the barriers are overcome?
Asteroid mining seems like one of the few objectives beyond near Earth space (communications and Earth observation) that have real profit potential - there really are valuable metals in vast quantities, the best opportunity we've found IMO, yet remains stubbornly uneconomic; moon, Mars for mining or colonies are much harder.
I also like to point out when "mine the asteroid belt" comes up... there are asteroids a lot closer (in distance and in delta-v), including in Earth crossing orbits with excellent solar power resources; thinking we have to go to the Asteroid belt to find asteroids (ie not thinking, ie assuming wrongly) isn't a good start to discussing how we might enable asteroid mining