Just a wild guess – developers lack soft/managerial skills. (Overgeneralization.) In companies, this is accounted for because developers are shielded by managers. But in F/OSS you get to interact directly with the developers. As for the why devs lack soft skills – hold your hats – programming is basically commanding. Without "thank you", without "please" and with lot of swearing. No time for pleasant bullshit. (By this reasoning, devs using declarative/functional programming should be more polite than imperative programmers, right? :D)

It was 4chan. You can read my comment history on Hacker News if you want to learn more.