More importantly it makes you think about your code in terms of logical, self contained, reviewable chunks. github makes you not care about commits. This ends up making it harder to scale contributors. You could not run linux on github. It would not scale. with git-contacts, you can cc everyone who has touched the chunk of code you’re touching based on git-blame. Lots of cool tools like this are unknown to github users. Also just having threaded review is huge, github doesn’t even have that.