Why the need to deny bias that others have experienced?

I’ve read (on this very board) of instances where people would use the word “Canadian” as a racial slur for Blacks; so I don’t think it’s a stretch to assume that someone who drops “niggardly” in casual speech is race-baiting (unless they are referencing Chaucer/Shakespeare).

Of course, they could be just naive; but that isn’t my first assumption…