I think this is completely wrong. See my reply to edw519 for my reasoning why, but the abstract is that I don't think potential is a constant across the population, or even a subset of the population -- like programmers. Aptitude = effort + potential. A good teacher can help, but won't overcome an incapable student, as much as the student may want to please the teacher.

Attitude is a lot harder to change than skill.

This has been said by a couple of others, and my first thought is really that it depends on exactly what people mean by changing a person's attitude. The theme seems to be that candidate A types are just antagonistic pricks who either want it their way or no way at all.

From the perspective I've gained, it's rarely that simple. When an employee gets branded as having an attitude problem, I'll see as often a problem manager as I will a problem employee.

In the cases of the problem manager, what I'll find is a manager who believes that the hierarchy is as hard as stone, and that employees have absolutely no place to question their judgement or the judgement of those above them. Any employee who might offer any sort of commentary or criticism are immediately branded as an attitude problem, and threatened into submission. The subsequent rebellion may take multiple forms, including them just going off into the weeds without listening to anyone about anything. Immature, perhaps, but in a pot and kettle sense. If you find disrespect going in one direction in a relationship, it's worth seeing if that same disrespect flows in the other direction.

Asserting more absolute authority, which seems to be the most common response, will only make this worse. Not everyone's value judgments are subject to overridding by fear and a desire to please others; I don't think we would want them to be, either.