You realize that word existed before the US was even a country right? You also realize that the word is used in many contexts with no relation to anything dealing with skin color or slavery right?
"Maybe they took not being racist a little too far, but changing a single word is hardly "insane" or "ideology"."
You've got your head in the sand and are oblivious to what's going on at a national level if you think this just involves a tiny one word change happening at GitHub. There's a broader cult like indoctrination happening with the current administration and it's cascading all the way down to schools and the workplace.
I'm really tired of hearing this spiel about how we shouldn't get upset because this is just one silly word. Well since it's filling children's minds with critical race theory in schools and training them they're subconsciously evil if they're a certain color I find it quite upsetting.
Btw here's the etymology of the word to prove your point even more incorrect https://www.etymonline.com/word/master