The question up for debate wasn’t where the majority of votes are—or were-within the Islamic community.
The question was whether ISIS could cause trouble in Egypt. My take is that there are plenty of home grown jihadis who are willing to die for their faith in Egypt, including those who will be willing to destroy the ancient glories of the Pharaohs. I don’t that precludes the fact that the majority of Egyptians may want to maintain them.
Aren’t there some who are already causing trouble down in Sinai. It was fundamentalist Muslim Brotherhood members, hidden among the military, that assassinated Anwar Sadat.
There's trouble, there are troublemakers, no question, but nothing that the army and regime can't handle. The Sinai is still considered a non-Egyptian province, as it was in ancient times, and the jokers doing the terror and killing don't consider themselves Egyptian for the most part. They are financed and armed from outside the country (iow, the Iranians) and cover is at a premium in much of the waterless hellhole that is most of the Sinai, so the terrorists operate in or near the various seafront resorts. They can't really run for it, because there's really nowhere to run.