They have all the ingredients to be a great nation. Great history and culture and good food.
No they don't, not by a long shot. Past history and good food are irrelevant to nation building, and their culture is in no way conducive to forging a modern nation state.
Cultural hurdles:
1) Ethnic and tribal loyalties are strong, and they trump any sense of a national identity. A nation-state can be formed only if people agree to the idea of owing allegiance to that nation, rather than to their ethnicity or village. This is also the reason why some places in the middle east and Africa have trouble forming strong nation-states. Allegiance is to their own tribe or ethnicity or warlord. (Yemen, Sudan, and to an extent even Iraq, Syria, Libya etc.)
2) Extreme poverty - Afghanistan is the one of the poorest regions on earth, and their total GDP is about 20 billion dollars. That is simply not enough to have functional civil institutions, like a judicial system, representative government at all levels (not just a parliament), building civic infrastructure, educating the population, providing healthcare etc.
When the organs of the state are non existant, it is difficult for people to owe any loyalty. The only authority figures they see in their lives are warlords or village shuras.
3) Lack of modern education, and especially an appalling lack of scientific and technical literacy. That contributes to the above mentioned poverty.
4) Frequent wars and conflicts.
I could go on and on, but the point is that Afghanistan is a place that cannot be expected to become a flourishing nation state any time soon. Contrary to your assertion in the OP, they have nothing that is necessary to become a modern nation state with a collective identity.
After all Pakistan started with nothing and even less than Afghans and could have gone the same way but didn't.
Why is this so?
Pakistan, like India, inherited many of the civil institutions of Britain. They also inherited the primary and higher education systems. Besides, during the freedom struggle, Indians developed a collective identity, and at the moment of independence,, the idea of India or Pakistan was more important than the idea of ethnic loyalties. The freedom movement was pan national, not based on ethnicity or regionalism or religion.