If someone decided they don't care about bias in the tech sector because the default git branch name was changed, they weren't going to and didn't care to start with.
This feels like a strawman - the issue isn't people deciding they don't care about bias because of this change, but rather that if tech companies are bending over so much as to make such an insignificant change to avoid seeming biased against minorities then how could bias in the tech industry exist at all?
Also, this kind of change might increase cynicism.
I'm confused by this question, aren't you essentially asking, "how can a problem exist if some people are presently taking actions that try to mitigate that problem?"
No, they're asking "what even is the problem if the solution is this?"
I wonder how many friends that attitude will win you.