In an interview I heard on CSPAN with Jessica Stern (I found the same point documented online in this article), she claims that most Muslims do not acknowledge ISIS as a form of Islam in the same way that most Christians do not acknowledge Identity Christianity as a form of Christianity. In the CSPAN interview, the claim was made in the context of their violent practices, and in the linked article it is made in connection to their sexual enslavement of women.
Is that accurate? Do most Muslims reject the beliefs of ISIS as a form of Islam?