There is lots of reason why competent developers would not actively participate to OSS or have public repos. I think you are holding applicant to an unreasonable standard that does not entails they are bad if not upheld. I have worked with some extremely talented people - far more than I ever could be - who had 0 contributions, 0 repos and publicly available code.

Why? Because they valued the time spent with their family and friends more. They got the job done which is ultimately what I pay them for. Which is all that matter really. Are they competent? Do they get work done? Can they potentially take-up bigger engineering challenges (i.e can they grow). Yes? Welcome at X co.

Why? Those people sound like terrible employees. Those are the people who come into work to punch the clock and get paid while saving their energy and creativity for their side projects, which is what they'd really rather be working on.

Shudder. Sounds like one chooses to work for you, or have a healthy life that involves non-coding/computer hobbies and relationships.

Maybe it's a good filter for us in the opposite direction.

Also 99.9% of the tasks I wish to do are solved so it's not like I'm going to make my life easier by solving the task. For the few that I find that I want I understand they require extraordinary resources/programming skill that I just don't possess.