The white male CEO of Larian has already summed up why Karlach's ending won't be changed. The ending they've written is the ending that a non-white woman from a racial group whom the story constantly tries to justify the oppression and dehumanization of "deserves", in his opinion. It's her fault for not being a white man human or elf and thus inherently deserving of sympathy even if they're among the ones being racist and abusive to people like her.
