It may have been caused by an incomplete editing decision. If you remove a few words the sentence becomes grammatical, if clumsy. Compare: > Technology robbed

It may have been caused by an incomplete editing decision. If you remove a few words the sentence becomes grammatical, if clumsy. Compare: > Technology robbed workers’ of what had been highly valued physical knowledge about a job: [...] ...with... > Technology robbed workers’ highly valued physical knowledge about a job: [...] Maybe the original sentence was the second one and was edited for clarity, but they forgot to remove the apostrophe.