No doubt there are some who utter "Brit" with venom, but it's not inherent in the word itself. I am used to hearing it, and using it myself, as a rather affectionate term. Let us not be too quick to take offence (or offense, depending on where you are).

Jews may accuse Ukrainians of anti-Semitism because the Ukrainians call the "Zhydy" and, knowing Russian rather than Ukrainian, they hear this as "kike"; in Russian the proper term is Evrei, and "Zhid" is indeed derogatory. In Ukrainian, "Zhyd" is the standard term for "Jew" and is not at all derogatory. So "Brit" may indeed be a slur somewhere, but not anywhere I have been.

Stephen