We really shouldn't be sacrificing whole words just to appease cranks who won't be satisfied anyway. The English language has subtleties and people should stop trying to conflate meanings just to feed the outrage.
Agreed. I'm all for inclusivity, but everybody knows (by and large) what a one's "dark side" means, and that it has nothing to do with ethnicity (which is what the GP is hinting at).. Viewers don't assume Dexter's *dark passenger" is a representation of a Black person, nor Dar(k|th) Vader (despite being dressed all in black, and coincidentally, even dubbed by a Black actor). Darkness is a well established idiom in psychology, and if there's any confusion about it, I wouldn't say it's "unwanted" - more like deliberately assumed, explicitly suggested, intended.
You're talking about a situation where priming is relevant. Your objection doesn't address the problem.