Re: Hold on a moment...
what you're describing is the everchanging semantics in language. its a constant battle between the progressives who are willing to modify words to convey new and better meanings and the regressives who cling on to their old definitions, scared their world view will collapse because words are changing around them.
you've implied that the desire to change language is authoritarian - that's true only if it comes with a real penalty ("omg i cant say the word i used to say cos people will be offended", isnt a penatly, it's petulance). if anything it's the desire to preserve language that's authoritarian as it prevents us from expanding the vocabulary and refining the syntax. its also regressive and fundamentally against the natural human instinct to evolve and discover.
long story short. Master and Slave are just words. Words which have no more value in their meaning for ATA connected devices on a mother board and no less value when describing treating people as property.
they're just words - don't cling onto them so dearly because the next generation will be changing them anyway.