if github isn't at the top of this list whatever tooling you use to find sentiment is broken, fundamentally.
The rough math is based on % of negative vs. positive sentiment. There's likely a ton of noise around github that diluted the math. I can look into though, thanks for the feedback.
While HN has been negative on Github, October was its best month in terms of # of new orgs using it: https://bloomberry.com/data/github/