People who can't easily demonstrate their skills are always at a disadvantage relative to people who can.

For every one person who is great but can't publicize any of the good code they write, there are a lot of people who simply suck. Differentiating between them is expensive (read: hours interviewing the good candidate, many more hours interviewing bad candidates) which is why the people with a good github/bitbucket/ftp server full of code are at the top of my list. If they all bomb the interview, maybe I'll move down the list to the people who's skills are unknown.

This simple reality is why one should demand more money from employers who impose restrictions on what one does outside of work.

On the flip side, I have very rarely found an interviewer who has actually read through my github code. It is more like they are scanning through an imaginary checklist of 'has github account, has repositories in it' etc. The other day I got asked by an interviewer if I knew python. This was rather strange to me because we had just talked about one of my github projects ...which was an ml library for python.

My point is that if having a github account becomes a silly barrier like having an education from top school, it kind of defeats the point of being fair whilst also acquiring good people.

When I was the interviewer, the most useful lines to determining competency tended to be find github code, ask pointed questions.

As someone who is now interviewing for a new job. I've had three interviews this week ask pointed questions on github contributions including requests for me to change things on the spot ( or talk through a change that might occur).

tl;dr; If you take a good practice and cargo cult it, you'll get bad results.

Exactly. A lot of work is proprietary and confidential. Should you have a side project to show, sure, if you can do that without getting fired, or worse sued. As a salaried employee, In the past, I have signed employment contracts that basically state they own anything I write. I sure I'm not alone.