This year, the Muslim holiday of Eid El-Adha fell on the same weekend as Black Friday, the famous shopping spree tradition. Best Buy, one of the retailers participating in the event, posted a season’s greeting on one of their flyers: a little circle with “Happy Eid El-Adha” above the giant “Thanksgiving” greeting. It was a gentle nod toward a minority group whose holiday happened to fall on the same day. It was a great gesture toward inclusiveness. No one could possibly spin glad tidings and season greetings into a negative thing, right? Think again. The noble gesture has caused quite...