I was thinking about a post about how much they would lose, and that cooler heads might prevail -- approximately 12% of their economy is tied to the tourist trade, I found -- but then Islam tends to be spread among the uneducated, and the poverty-striken.
They are told that while their life is a struggle, Allah will reward the strong and obedient. So by their thinking, destroying the tourism industry would simply create more soldiers for the cause.
In other words, they're all insane.
I personally wouldn't pay Egypt a dime to see them.