I think the author's point is that it WAS working, up until 1924 and the deposition of the Caliphate. Then in the modern era, it suddenly became hopelessly outd

I think the author's point is that it WAS working, up until 1924 and the deposition of the Caliphate. Then in the modern era, it suddenly became hopelessly outdated - and unfortunately since, so-called "Islamists" have defined themselves on the opposition to other principles (secularism, nationalism and the like) instead of defining themselves in terms of their own ideas.