> as the market for cotton cloth matured in the mid-20th century, further automation no longer generated such increases in demand and new technology slowly eliminated jobs in the textile industry.

This seems to be a counterpoint to his thesis: Technology does indeed create unemployment if all demand has already been satisfied.

His point should thus be stated with a caveat: Technology does not destroy jobs as long as demand increases along with the increased supply. In order to know whether robots will steal our jobs, we have to first determine whether human demands are already being met or not, and it seems plausible to me that they nearly are today (though the inverse also seems plausible).