This is a topic of immense complexity and it's all-too-easy to oversimplify things, so take anything-including my post here-with a sizable grain of salt.
Nevertheless, I suspect that it's not liberal democracy or "pluralism" that is specifically incompatible with the "Islamic world" (a world that, we should never forget, is
extremely diverse in historical experience, culturally, ethnically, socioeconomically, and yes, politically); but that, for many of the world's Muslims, these ideas are so obviously associated with Western cultural and economic imperialism-to the point where "liberal democracy" is just another word for Western hypocrisy.
Whether Muslims-particularly, but not exclusively, in the Middle East-are right or justified in feeling this way is kind of beside the point. The reality is that many of them do believe this.
Here's an excerpt from an interesting article (from 1992, FWIW) that touches on that theme (bolding mine).
http://www.merip.org/mer/mer174/liberalization-democratization-arab-worldAlso, Political Islam/Islamism didn't really begin to emerge until the early 20th century-you know, around the time of the collapse of the Ottoman Empire. I'm sure that was just a coincidence, though.
