They are views directly related to that persons job responsibilities. So Github endorses the views by hiring the person and putting the person in a leadership role. It would be different if the views were not directly related to the persons job responsibilities and policies of the company.
From my experience/observation, I believe this is what EmberJS is trying to do, combine best practices of the past with new learnings today. SmallTalk for example, heavily influences the framework, as does a number of historically successful frameworks. I am not arguing that Ember is perfect, but I believe what you state is part of their objective.
How does he show initiative? A couple of reasons people work on side projects are to gain experience and show initiative. While I'd agree that 1, 2, and 3 are good things....I would also say that side projects are a way to achieve #2.