...the degree of toxicity of the soil, and necessary techniques to detoxify it, the difficulty in excavating and beneficiating it, the types of chemical reactions that will be required to extract useful minerals from it, the maintenance requirements for using machinery there…toxicity of the soil
He's referring to highly reactive perchlorates in mars soil. The highly reactive is the good part. It means when they go from a toxic environment to their clean shirtsleeve habitats it will be very easy to clean. They may just need some humidity in the airlock and correct pressure flow from their main living area. I've worked in such environments and it's no big deal. Mars doesn't need toxic soil to kill ya. They will follow certain protocols is all.
excavating and beneficiating
This is known as grasping at straws. Mining is not a recent invention. Humans have been doing it for thousands of years.
chemical reactions that will be required to extract useful minerals
More straws, this time only hundreds of years (for modern chemistry.)
Things wear and things break. Now we're back to the thousands of years threshold. This deserves a bit more discussion. You know who fixes things? The people these ridiculers look down on. They have contempt for those that can do things they can't do themselves. It's unfreaking believable. I can't true a lathe, something most machinists can do with out even thinking about it. But I would never disparage them for not being great CNC programmers which is not generally their thing. They can repair parts. They can make those parts from raw material. They can make the tools to make those parts. They don't even need a 3D printer to do any of it, but will certainly use one when available.
But I'm the delusional one!!! What disappoints me is from all the intelligent commentors over there to jump on the ridicule band wagon rather than use reason. I know they know better.