Why Modernism didn't Take Place in Afghanistan?

In his introduction in The Emergence of Modern Afghanistan, Vartan Gregorian, mentions a quote from Mohammed Ali’s book, A New Guide to Afghanistan, as follows:

“No country comparable to Afghanistan in size and no people approaching the Afghans in historical interest and importance have received so little consideration at the hands of modern writers as have Afghanistan and the Afghans.”
For its importance and its relevance, Gregorian, puts this quote, contextually, in the 19th century of Afghanistan in which he argues that Afghanistan, for the most part, was culturally isolated, and protected as a parochial region in the Muslim world. That is one of the reasons that Afghanistan remained an unknown region to the rest of the world. He then draws a bigger picture by putting Afghanistan in the colonial frame; Gregorian says that causality of this “isolationism” and “parochialism,” relates to the fact that Afghanistan never undergone of a period of direct, and intensive European colonial rule.

This kind of argument has always made, and for the most part, it is true that Afghanistan in the 19th century had been thrown into the ditch of negligence. In part, colonialism could be blamed for this negligence, on another part, imperialism, however, by in large, it was the Afghans who had been the most neglectful, and ignorantly resentful to spread of any modern, or, European thought in their country. The effect of the harbouring resentment, of course, as Gregorian mentions in his book, was almost a total isolation that its effect has been destructively but invisibly palpable throughout the 19th and 20th century.

There was a chance, at the time, for Afghanistan to layout the ground and expect the waves of modernism, or, European thoughts, which could help Afghanistan not to be completely ignored. Unfortunately, however, it was the tribal Afghan Kings – who were mostly Pashtuns – were unable to understand the necessity of basic human needs, let alone modern thought, and developmental tools; they rather dragged Afghanistan into their Pashtun tribal domination, Pashtun parochialism, and Pashtunwali (a non-written tribal code of conduct of the Pashtuns). 
Tribal groups among Pashtuns began fighting over power – that who should rule Afghanistan – and as a result of blood feuds, they not only wrecked their own bases of tribal unison, but they wreaked havoc on potentiality of human development of other tribes in Afghanistan, namely the Tajiks, the Hazaras, and the Uzbeks. Therefore, Vartan Gregorian’s argument is legitimate, and understandable that if, today, one wonders why modern writers neglected Afghanistan, the clue is to dig into the history of modern Afghanistan, specifically, the period of 18th and 19th century.