There is also the popular implication when there is a girl on twitter starting trouble again, they're not coding and trying to claim some form of discrimination, instead of developing programming skill.
You can't--and obviously I mean in the "if you're a basically functioning, mostly vertebrate human being it's morally repugnant" sense of "can't", not the physical, over-literal sense that I feel like you're going to use--blame shitty workplace behaviors (and this isn't the first I've heard of GitHub having problems) on people not knowing how to code. I mean, what kind of world do you want to live in where you can excuse mistreating people because they don't "develop programming skill"?
Actually, don't answer that. I don't want to know what kind of world you want to live in.
Edit: I see from your profile that you're an undergrad. Hopefully you'll grow out of the attitude that only super-coders are valuable to a project, like I did.