Public and open-source contributions aren't a measure of skill, in fact they're not a measure of anything other than public and open-source contributions.

Personally I try to keep all of my work as private as possible. There is no particular reason, I'm just a private person.

Do you really want to work for a company that measures competence based on pissing-contest and attention-whoring mentality?

"Public and open-source contributions aren't a measure of skill..."

Exactly. Because they're falsifiable. I'd personally rather work for people who value skill, not falsifiable data.

right but many companies try to take a shortcut - they think the best measure of skill is github.

To be fair, it's hard to qualify "skill", so shortcuts are very tempting.