I was well aware of GitHub's very problematic past, from its promotion of meritocracy in place of a management system to the horrible treatment and abuse of its female employees and other people from diverse backgrounds. I myself had experienced harassment on GitHub. As an example, a couple of years ago someone created a dozen repositories with racist names and added me to the repos, so my GitHub profile had racial slurs on it until their support team got around to shutting them down a few days after I reported the incident. I didn't get the sense that the company really cared about harassment.
As a seasoned developer I have certain quirks, opinions, and common patterns that I fall back on. Having to explain to another person why I am approaching a problem in a particular way is really good for helping me break bad habits and challenge my assumptions, or for providing validation for good problem solving skills.
Asynchronous communication is sometimes necessary on a distributed team, but never in my career have I seen it taken to the level that GitHub has. Asynchronous communication is definitely not my strongest area. When I see a text box on screen, I tend to be very terse and direct instead of typing out a wall of text.
GitHub has made some very public commitments to turning its culture around, but I feel now that these statements are just PR. I am increasingly of the opinion that in hiring me and other prominent activists, they were attempting to use our names and reputations to convince the world that they took diversity, inclusivity, and social justice issues seriously. And I feel naive for having fallen for it.