Instant feedback type problem solving is great for ADHD people, not to mention that unlike other professions, software engineering isn't licensed and in a lot of cases doesn't even require a degree and so a wide variety of people can work as one.
I think a lot of people who work in high stress coding environments try to overcome their human limitations (e.g requiring rest, sunlight, communication) via stimulants or some other, and chalk up the neuroses produced by the vicious cycle of stim-work-stim-work as a weakness inherit in themselves
Judging by the conversation on this story, everybody on HN is a smug non-coffee-drinker. I'd guess it's just self-selection (maybe cross-pollinating with the fact that software development tends to require either mental discipline, or hyperfocus...)