Charlie,
Why especially non-Jews? Does your Rabbi believe that Jewish people are less deserving of respect than non-Jews? That it is a bigger chilul Hashem to be impolite to a goy than a Jew? That makes no sense at all. Olom hafuch ra’isi.
And for the record, I am horrified by some of the stuff that people post and probably not always the same stuff that you have been embarrased by.