When you look at Muslim history, you can see a trend for modernization in 19th century. Ottomans were changing their attitude to religion and modern world, other places were also following the trend.
In 20th century, however, came a backlash and a return to primary sources movement. This was mostly funded by Arab Wahhabi kings of Arabia. Their vision about the religion was not organic, they were not believing any change of beliefs due to historical situation, they were considering themselves Salafi that is immediate followers of the Prophet. Although Turkey was mostly secured from their ideology, currently when you say Sunni Islam it's mostly understood in terms of these people, unlike a century ago where the Sunni Caliph could also be a painter or a composer. (Can you even imagine Saudi King to be a painter of some kind? The last Ottoman Caliph was.)
In 1916, when the Sharif of Mecca agreed with the English to follow a course of independence for an Arab Kingdom, their ideological arsenal against the Ottoman Sultan was Wahhabism. This ideology was used to incite a revolt against Ottomans, because they need some religious justification to revolt against the Caliph and blaming his deeds from a point taking its source from infallible book was the most guaranteed. This was indirectly supported by the British at that time and flourished since then. Their insistence to return to basics is just a big anachronistic lie. You can't reverse the time and become an immediate successor to the Prophet, but you can use his name and Islam's basic sources to rally people around you. The basic reasoning of radical Islam is this: Allah said this, Allah said that, anyone who doesn't accept this is an infidel and his blood is permitted. When traditional ideology lost power and appeal, people turned into such snake oil ideologies that claim to cure all disease in the Islamic world. The current terrorism is a natural result of this. Because of this snake oil ideology of ignoring history and accepting the book as our only saviour, we are sicker than ever.
When you consider yourself an immediate successor to somebody, despite 1400 years in between, you strive to transform the world into a world that you can really be a successor. It's not possible, though understanding that it's not possible and Allah didn't set all rules in the Book or the Prophet's Sunna is not always applicable, takes time and much blood.
I hope Muslims are understanding that our problems are not that easy. You can't solve them with an infallible book. Our attitude is primarily a showcase for brain laziness. Instead of thinking real solutions to real problems, it's much easier to turn to the book and agitate. I don't know where this agitation will lead us but I'm always optimistic that we'll have some major shifts in Islamic thought when petroleum stops funding this easy-cheesy ideology.