I can identify with some of what the author has saying, as I've struggled with a pessimistic attitude throughout most of my adolescent and adult life. However much of it was formed long before I learned to code. I've recently been working to be more optimistic as I think it can be learned.
However, I suspect pessimists tend to make good programmers rather than programming causing someone to become more pessimistic.
If you're interested in understanding some of the psychology between Optimism and Pessimism, I recommend reading Learned Optimism by Martin Selligman. http://amzn.com/1400078393
"However, I suspect pessimists tend to make good programmers..."
It might also be that pessimism could limit programmers' capabilities by making them afraid to take on ambitious problems. Being somewhere in the middle of the spectrum might make someone a better programmer than being either too optimistic or too pessimistic.
However, I suspect pessimists tend to make good programmers rather than programming causing someone to become more pessimistic.
If you're interested in understanding some of the psychology between Optimism and Pessimism, I recommend reading Learned Optimism by Martin Selligman. http://amzn.com/1400078393