Well, politeness is a conservative value too. There are PC excesses, but that doesn’t mean people went around being obnoxiously rude before PC.
Well, then, attack it as rudeness instead of escalating it into racism, which is the game that is trying to be played here. If every perceived slight is inflated as such, there never will be harmony.
As I said, I watched my father’s generation come to peace among the European ethnics. A lot of “polacks” and “wops” were bandied around by tough construction workers who laughed it off sincerely and moved on; something that would have provoked mass fights decades early was put into proper perspective through humor.