Here. This article was made the rounds recently because it's interesting. What makes it interesting is the conclusion (backed but tons of study):
"In sum, we present this article as an exploration into why people tend to hold overly optimistic and miscalibrated views about themselves. We propose that those with limited knowledge in a domain suffer a dual burden: Not only do they reach mistaken conclusions and make regrettable errors, but their incompetence robs them of the ability to realize it."
In other words, the folks that are most incompetent don't even know it so that they can look for ways to improve themselves. Why don't they know? My take is that we're too damn polite to tell them, preferring instead to complain about them behind their backs. Is that nicer? Sure. Is it better for the incompetents of the world? No.
On a lighter note, I love how the researchers go "meta" at the end of their article:
"Although we feel we have done a competent job in making a strong case for this analysis, studying it empirically, and drawing out relevant implications, our thesis leaves us with one haunting worry that we cannot vanquish. That worry is that this article may contain faulty logic, methodological errors, or poor communication. Let us assure our readers that to the extent this article is imperfect, it is not a sin we have committed knowingly."