That is a direct paraphrase of the abstract of Kruger & Dunning, 1999[1]:
"The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it."
Now, it may be possible that the definition has evolved since then, but as the term Dunning-Kruger effect is named after this paper, I think it's safe to say that Wikipedia is at least partially wrong in this case.