This seems like a weird move to take. From what I can tell, there's no clear evidence of gender-related wrongdoing* . There is one person's strong allegations of it, and a handful of accounts saying otherwise (of mixed trustworthiness).
So, whether you believe there was gender-related wrongdoing depends entirely on whether you believe Julie Ann Horvath or an independent investigator, or neither.
As such, it seems like the only reasonable conclusion for an outside party considering an action related to github (going to work there, partnering with them, or even just using their product) is "we don't know."
The only way we could know, with any actionable level of certainty, would be if this went to court. Until that happens, though, any punitive action we take (like boycotting github, or ending partnerships with them), is based on a guilty-until-proven-innocent approach founded in a single person's accusation. That reeks of witchunting, and I'm more than a little concerned by it.
* Everything github has said seems to indicate only non-gender-related wrongdoing, specifically the founder's wife pressuring (unintentionally, according to her) employees into helping with her charity.
