Mokyr is writing about the British Enlightenment which was very different from the French. It was more involved with science and industry than with political or philosophical theories.
In the past I'd have agreed with you and identified the Enlightenment with the French Revolution and later totalitarian utopian projects. But the context has changed.
Years ago we thought in Cold War terms. Today the encounter between the West, which experienced the Enlightenment, and the Muslim World, which didn't, influences the way we think about the 18th century.
The point had to do with the dishonest historiography of the left’s “Enlightenment” historians who set about claiming that every positive development or every bit of progress was somehow part of the “Enlightenment”. What happened in England in political thought (the good parts) and in science, and especially Scotland, are a legacy of the Reformation.
Postmoderns are particularly adept at misappropriating things by simply saying that there were many “x’s” (e.g. “Enlightenments”) so that they can confuse peopole by grouping things that are dissimilar in principle under the same general term. The political uses of this sort of thing are legion.
Mokyr has no idea what he is saying.