You're forgetting Onion2k's point that it's cheaper for companies to hire robot-replacable employees because it loweres the wages of the non-robot-replaceable labor. Under that theory, the reason they can't bring in the robots is that their remaining labor costs would increase.

Personally, I don't know why that would be, given that companies pay what they need to get employees to work there and nothing about the NRR's job would change if the robots came in.