IMHO the reason is lack of direction. Like a rudderless ship, to date we have not been abled to decide which direction we want Pakistan to take. There is a division in the Pakistan society.
The 'fundoos'; whos aim is to take Pakistan back to a dark age Utopia, where the radio, video cassettes & TV are all banned and women are forbidden to go to school. These forces send out burqa clad lathi wielding women to beat up ladies taking part in marathon and blow up girls schools.
On the other side are liberal fascists such as me; who would like Pakistan to be a modern liberal state; something that our founding fathers, especially the Quaid had in mind.This division is not limited to Madarassah students and the English medium educated elite; instead it is present at levels of the society.
Urdu media stalwarts such as Hamid Mir, PA senior officers such as Hameed Gul, Oxford educated ex playboys such as Imran Khan are all fundoos. When you consider that Punjab Chief Minister and his Law Minister are also appealing to Taliban for clemency; result can only be chaos.
Unfortunately, PPP and their allies who represent liberal forces; dont even know what good governance means. These leaders may be liberal in outlook, but their appetite for corruption at all levels appears to be limitless.
Thus the blame as to why the last 62 years have been wasted lies squarely on the shoulders of our leaders. Regret to say that after 1951, nearly all of our leaders, whether civilian bureaucrats, military or political; have been found lacking in statesmanship. You cannot completely absolve ordinary Joe public from the blame either. Why the public keeps voting the same people again and again, almost like musical chairs?
Unless Pakistanis decide once for all which way they want Pakistan to go, we are doomed to muddle thru aimlessly as we have done for the last 62 years.