Please, correct me if I'm wrong, but as far as I can tell, the first author is an undergrad CS student. If I had to pick anyone to do a study like this, it wouldn't be someone who studies CS, it would be a social scientist. That being said, that doesn't preclude this from being good work.

I lost confident that this would be good work after reading the fourth sentence, though:

"Research suggests that, indeed, gender bias pervades open source. The most obvious illustration is the underrepresentation of women in open source; in a 2013 survey of the more than 2000 open source developers who indicated a gender, only 11.2% were women"

This is a textbook non-sequitur. It is trivial to show that a gender imbalance in a group or field, even an extreme one, is not proof of gender bias in that group of field; it's not even good evidence.

To be perfectly honest, after reading more of this "study," it's pathetic that this made it through peer review. Shame on this poor child's advisors.

As I suspected, PeerJ is an open-access, pay-to-play journal. I have to ask what kind of "peer-review" is involved. A science blog should have better standards than this.