> Why are they so invested in putting up blinders to ignore that "meritocracy" in the context of open source development doesn't carry that demeaning connotation
They aren't. They are arguing that it should be because, as arguably is part of the subtext of the original usage, what “meritocracy” used non-ironically denotes is very much something which humans fundamentally do not do, or even approximate, without deliberate and active correction for social and cultural biases of the exact type that the description of “meritocracy” is generally, and specifically in the case of those who apply the term non-ironically to the open source community, used to deny the need for.