Just because a sample consists of 50 companies and 200 interviews hardly makes that a sound sample, given no information about how those companies were selected, and given no attempt to compare those companies to successful companies. For example, 5/7 of these traits easily describe Steve Jobs.

Furthermore, just because someone is an academic authority hardly makes them less liable to fall for the cognitive biases that davidkatz mentions (that we color character traits into stories that fit the result). It goes without saying that we all have a strong bias to attribute other people's actions to their personality rather than conditions in their environment over which they have no control (http://en.wikipedia.org/wiki/Fundamental_attribution_error). We generally don't apply this error to ourselves.

The classic example is that if someone trips over a rock, you'll tend to have the impression that they're clumsy. If you trip over a rock, you won't think you're clumsy, you'll just say to yourself that the rock was sticking out.