Projects like Chromium and ChakraCore are not being written in anyone's "spare time." It would be nice if people would stop conflating Open Source with unpaid hobby work. The projects analyzed in this story represent billions in paid labor.
In other news: people who have to focus on detail oriented tasks often make mistakes.
Happy now? Sheesh.
people who have to focus on detail oriented tasks often make mistakes
Whether they're paid well or not.
You clearly haven't worked in a commercial closed source setting.