I cannot speak for them, but it is very different to not want a foreigner who is not from your religion to date a Muslim, than it is to want to kill all Jews. Of course, it is very bad to take it to the level of a beating, or to make that choice for someone else, and what they did is bad. What I often see is a few zelots in a groups of people who don't care for Jews, but don't want to kill them. It is very difficult to stand for a stranger who is outside your culture, and defend them, without being labeled as an enemy of your own culture. My father was clear to us that Jews were not evil because they are Jews, just as Muslims are not all good because of their religion. He was friends with a small family of Jews living in Gaza near us. I do not think he would want me to date them, but he was happy that we could be friends.