I respectfully disagree.
I understand that the idea has not been incorporated within 99.88% of the Islamic world, but trying to prove the point by through etymology is just silly.
As I read it the author's point is that while the word is familiar to the Muslim world - the concept is not - I guess his prrof that the Muslim world knows what democracy is even while rejecting it is that their word for democracy is the same as the Greek. Maybe it's a stretch to put it in that way.