Any company that tries to throw out traditional processes needs to have a very clear understanding of why those processes/rules existed in the first place, and why they're irrelevant.
Certainly there are differences between highly motivated technical staff and many other professions, but it's not like most companies go around making rules and processes to make their lives harder.
Also, on another point, Github believes itself as a very much hacker culture. And if it's a hacker culture, shouldn't they believe in the Hacker manifesto, where they don't discriminate on religion, race, gender, but on their ability to code?