Because of the horrible massacre at a mosque with Sufi tendencies in Egypt, there are a lot of “explainers” out there about sectarian divisions in Islam. The one in The New York Times, Who Are Sufi Muslims and Why Do Some Extremists Hate Them? could be worse. This portion especially gets at the major issue:
For a time, beginning in the 12th century, Sufism was a mainstay of the social order for Islamic civilization, and since that time it has spread throughout the Muslim world, and to China, West Africa and the United States. As Sufism spread, it adapted elements of local culture and belief, making it a popular practice.
Alexander D. Knysh, a professor of Islamic studies at the University of Michigan and expert in modern Sufism, describes it as a “very wide, amorphous movement” practiced within both the Sunni and Shiite traditions.
Specific claims about Sufism beyond the most general fail because vast swaths of Islamic history and Muslim peoples and practice are Sufi. In the modern western media, there is an unfortunate tendency to dichotomize Islam into a harsh and fundamentalist form and a moderate and mystical Sufi variety. Though a small minority of Sufis have drifted toward very heterodox beliefs, the vast majority are orthodox Muslims who also adhere to a school of Islamic law.
And Sufis are not all pacific saints. In the 19th century Libya the Sensussi Sufi movement was critical in the continuation of the trans-Saharan slave trade, and later served as a major focal point for violent resistance against the Italian colonial project. The great anti-philosopher of the medieval period, Al-Ghazali, who is generally agreed to have ushered in the decline of philosophical thinking within orthodox Sunni Islam, was a Sufi.
The question should not be about Sufis. Sufis are not moderate or mystical Muslims, they are simply Muslims. That is, they’re the mainstream. Rather, the crux of the issue is that violent radicals have emerged from the soil of Salafism. Not all Salafis are violent. But violent Salafis are the ones who regularly target other Muslims and their holiest of sites.
Salafism is a modern movement of the past few centuries. Like Protestant Fundamentalism, it is a product of the engagement of traditional religion with the modern world. Self-consciously Salafist Muslims have never known a world where the West was not dominant. Therefore it is no surprise that they look to the accrued tradition of Islamic civilization and see in it failure and decay.
Like some Radical Protestants, the Salafists imagine that they are creating a community of Muslims who are true to the path of the religion in its earliest years before it became tainted with monarchy. Basically, Salafists wish to transform Islam from a religion of history to one of pure axiomatic abstractions.
Why do Salafi radicals attack Sufis? Their tendency to engage in takfir against other Muslims goes back to the proto-Salafi Wahhabists. And Sufi Islam, with a venerable history going back more than 1,000 years, is naturally going to be the target of Salafi rage because it was the Islam that failed to stem the tide of Western ascendancy, the Islam that witnessed the slow and gradual decline from the greatness of the 8th and 9th centuries. The children shall eat their own parents.