Github isn't necessarily a new concept nor is submitting links to code sample repositories as part of a programmer's 'portfolio' Forgive my naiveté, but why is

Github isn't necessarily a new concept nor is submitting links to code sample repositories as part of a programmer's 'portfolio' Forgive my naiveté, but why is this a topic of debate now? Did something radically change? Weren't you all doing this before Github existed?