Dan Calic sums this up briefly and very well. Allegiances to the family unit, the clan, and the imam all supersede allegiance to the law, or what we might call the institutions of civil society; fundamentalism is strong and, even where not constituting a demographic majority, is well organized and powerfully devoted to the cause. The latter point is not so hard to grasp for most Westerners; the former--a different, hierarchical societal structure, with basic family, clan, and what we might call "clerical" loyalties--is indeed difficult to grasp for people who unthinkingly assume that Western societal structures prevail everywhere, and that a supposed universal desire for freedom means democracy is just waiting to spring forth. Again and again and again, cultures and civilizations differ from each other, sometimes radically.
To the points Calic emphasizes can be added the ideologies of sharia, jihad, Islamic supremacism, male supremacism/misogyny, anti-Semitism, anti-Christianism, anti-Americanism, and anti-Westernism. Not, of course, universal in Arab (or other Muslim countries), but very widespread and sedulously inculcated.
Plus: widespread consanguinal marriage; very high frequency of child abuse and spousal abuse.
Mix, and you get...something other than democracy.
