I've seen this argument before, and I think its a bit strange. It doesn't seem to take into account how any industry develops. Just because you have a viable way of getting the materials back to earth does not mean you're able to flood the market. First, the platinum market is something like 200 tons per year. So at around 100 tons per year, I guess we could say we have flooded the market. But what would that require? It would require a mining operation that can produce 100 tons per year, or a few hundred kilograms per day. That in turn would likely require a similar amount of oxygen and hydrogen, most likely also mined, for transportation between asteroids and earth. Then you'd need the infrastructure for the transportation and the fuel mining and the platinum mining rig itself. It seems pretty obvious to me that this requires putting many hundreds if not thousands of tons into LEO. In other words, we're nowhere near having the infrastructure for that kind of scale to be plausible right away, no investor would go for a plan like that. Secondly, no one really knows how you'd build this system, so we'd need to try several different ways of doing this, and the first ones will probably not be profitable. The first attempts will be mostly about demonstrating the possibility and testing various systems. If profitability is unlikely, you'll want to keep the scale as small as possible. I'd say one ton per year is a very large scale for the first attempt. I think it would take atleast two decades between the one ton scale to the 100 ton scale. And all the while, people would still be unsure wether this was profitable in the long run or not, just like it is with regular mines. It would not be like the gold rushes in the americas, where people suddenly discover a resource that was cheaply available. Instead, it would be like modern mining operations, where everyone is mostly aware to some extent that the resources are there, but nothing happens until enough investors decide that it's worth the risk to try and develop it. This means it will be a very careful development (that might at any time stop to be resumed a few years later with new investors) with relatively little real competition because, frankly, few people believe in it. And again, the scale will be kept at a minimum, because not even the investors who do believe in it want to make the risk bigger than it has to be. So yeah, it's been said that this whole asteroid mining thing is fantasy and science fiction, and there's probably some truth in that. But the "flooding the market"-criticism is even more sci-fi in my opinion. I don't see how anyone who understands the mining industry or the space industry could believe THAT to be a significant problem here.