I'm not very sure about Github. There's real hard gold and stinky soft gold in Github. For a project leader or people like me it's easy to separate real gold from stinky gold. Don't misunderstand me. Everyone can post his gold on Github. But was the gold his, or infinged gold or stolen gold? Nobody knows because Github itself does not care about the ownership.
Just ask Bill Gates or Mark Zuckerberg why his company employs mostly high-qualified people in Research and Development (R&D). Even my company, I have only MS people who work for my. The point is, as I mentioned above, that an University certificate is the only proof that this (wo)man did have the courage and durability to complete an "unpleasant" project: STUDY. And if (s)he could do that (s)he would be able to complete another unpleasant project for the company.
Also, anyone who believes that he could start as an IT developer without any qualification is a fool, a daydreamer, a fantasist. An IT developer without imagination because of lacking the basics is a pitiful (wo)man who lives in stress, insomnia and hypertension. A wreck when (s)he turns 40.
How many Bill Gates and Zuckerber does the US have? Two out of 310,000,000 Americans. One Bill Gates and One Zuckerberg.