We will always have a use for orbital mining as long as the amount of solar energy passing inside the Moon's orbit equals the world's known fossil fuel reserves *every minute*. It's not the metals or water that are important, it is access to that enormous energy flow, which lets us do most anything we want.
The assumption made by Elvis in his paper is wrong, though. 4.5 km/s from Low Earth Orbit only accesses 4% of the asteroids, but you don't want to mine from Low Orbit. You want to mine from the vicinity of the Moon, where you can get a free 1-2 km/s gravity slingshot from the Moon in both directions. Using the Moon plus 4.5 km/s propulsive velocity gives you 8.75 km/s relative to Low Orbit, and that accesses 60% of Near Earth asteroids. So right there you have a factor of 15 larger sample.
4.5 km/s is derived from the Tsiolkovsky Rocket Equation, and implies your propellant burn is 172% of your payload mass. However that equation assumes you start with all the propellant at the start of the mission. If you are mining for propellant, you can do that at several locations in Near Earth space, not just near the Moon. Refueling changes the propellant needs from exponential to linear with delta-V. Let's say you can refuel twice during the trip, for a total of three propulsive intervals. if you are allowed 172%/3 = 57.33% propellant each time, you can travel 2.04 km/s x 3 = 6.12 km/s velocity change for the same amount of propellant. Doing the same calculation relative to LEO, we get 10.4 km/s above LEO as our reach, which lets us access over 70% of Near Earth Asteroids.
Finally, let us assume electric propulsion, which has an exhaust velocity of 50 km/s, and that we can extract 20% of the mass of our vehicle as propellant. That gives us a range of 9 km/s per fueling stop. With 3 stops we can reach 27 km/s, which lets us not only access 100% of Near Earth Asteroids, but is beyond Solar System escape velocity. That means we can mine anywhere in the Solar System - Main belt asteroids, Jupiter Trojans, Kuiper Belt. The ability to refuel plus use of electric thrusters is a complete game changer.