Your point? Mine is that they are leaving Muslims alone, even when their Islam is incompatible with ISIS. Many Kurds are Sunni, but their identity means that they are incompatible with ISIS. Incidentally, many Kurds are Christian, Yazidi, Shiite, Jewish and Zoroastrian, although the Jews are long since gone from Iraq and Syria, and the Zoroastrians are largely in Turkey and Iran. But ISIS is targeting only the non-Muslims.
FYI and for review