That's not the sort of activity the article was taking aim at; the author's example of regulators and compliance officers was appropriate, I think. The agents may have come to act in a manner where much of the labour that each engages in is justified by the actions of the other, and so the bulk of their combined labour cancels itself out and we have little increased utility on the whole. Whereas your trade of shellfish and peanuts don't behave in this manner.