Honor killings, or the like, are historically prevalent in a host of communities worldwide, irrespective of religion. Quotations from religious texts (usually taken out of context) or traditions are simply used to bolster the parents' or communities' justification for violence. So it is with many calls to violence, whether aimed at a nation, sect, or individual.

Such things are most prevalent amongst the economically and educationally poor, and Islam happens to be dominant religion in many of the poorest regions of the earth. If they were another religion, the killings would not stop; only the holy text cited would be different.