What's the deal with programming, as a careeer? It seems like the lower levels at least should be readily accessible even to people of thoroughly average intelligence but I've read a lot that leads me to believe the average professional programmer is borderline incompetent.

From what I can tell the average person is borderline incompetent when it comes to the 'actually getting work done' part of a job. It is perhaps slightly more obvious with a role such as programming where output is somewhat closer to the level of objective physical reality.