The Catholic Church used to say that "The Church grows from the blood of Martyrs". This is perhaps true of Islam now.
Then there is another saying that may apply: "The Enemy of my Enemy is my Friend". Well, Zionism and America have been everything in their power, economically and militarially to make themselves the most hated enemies in the World, and it has been Fundamentalist Islam that has stood most visibly against them. It used to be Socialism and Communism, and in many of the same areas. But now it is Fundamentalist Islam that is willing to embrace all of the young unemployed men, and give them purpose in life that they would ordinarily find in their Work.
You would think that American Capitalism would arrive at the easy insight that most people on the World could be bought off, and bought off relatively cheaply. Jobs. All it would take is Jobs. But Capitalism is incredably short-sighted and is willing to lose a billion dollars in a year to save a dime in the next quarter -- they never see further ahead than the next quarterly statement. so it is this mentality that sees 50% and 60% Unemployment in these Islamic Countries as 'saving them money' -- they have already been "downsized" and so their job is done.
As for all of the Appearance Issues. You are talking about the Enemies Uniform. People are drawn to Social Uniforms. Hippies used to wear blue jeans and wore their hair long and matted. Motor Bikers wear black leather and old nazi helmets. And people who will bomb Zionist and American Interests around the world will wear turbons and keep long untrimmed beards. It is really no mystery. People like to feel as though they belong, and when they do, they do everything they can to look that way. "Birds of a Feather".
This is why it was SO ridiculous for America to make an Enemy out of Saddam Hussein. The man wore a BUSINESS SUITE, as though he were working for IBM or General Motors. He WANTED to be a Good Western Capitalist. And was it really asking so much to have let him keep Kuwait -- a Land of petty Kings who still dressed distainfully like beduion camel herders from 200 years ago. Now, the people in line to replace Saddam Hussein -- they dress in Turbons and keep untrimmed long beards. We deposed a "Friend" and have substituted "Enemies", at least as far as the 'uniforms' go.