I'm not saying you assume someone who doesn't have open source work / contributions isn't necessarily a going to be a good employee. I'm just saying it's materi

I'm not saying you assume someone who doesn't have open source work / contributions isn't necessarily a going to be a good employee. I'm just saying it's materially harder to tell in comparison to someone with the same resume and a publicly-viewable history of contributions. Any time you have a choice between the unknown and known, it's going to favor the latter.