GitHub customers really are willing to do anything besides coming to terms with the reality confronting them: that it might be GitHub (and the GitHub community/userbase) that's the problem.
To the point that they'll wax openly about the whole reason to stay with GitHub over modern alternatives is because of the community, and then turn around and implement and/or ally themselves with stuff like Vouch: A Contributor Management System explicitly designed to keep the unwashed masses away.
Just set up a Bugzilla instance and a cgit frontend to a push-over-ssh server already, geez.
The community might be a problem, but that doesn't mean it's a big enough problem to move off completely. Whitelisting a few people might be a good enough solution.
Obviously technically the same things are possible but I gotta imagine there's a bit less noise on projects hosted on other platforms