Why do Pakistanis think Afghanistan is 100% Pashtun?

Hello, I am a non-Pashtun from Afghanistan, I can't help but note now how ignorant the average Pakistani is regarding the ethno demographics of Afghanistan, they think the country is majority Pashtun (when there is no majority in Afghanistan) & that Pashtun ethnicity & Afghan nationality is synonymous, it's been bothering me a for a while now because due to this misconception Pakistanis think they are entitled to any disrespect towards Afghanistan's people, yes a Zadran Pashtun killed your prime minister, yes a Pashtun president rejected the Durand line & attempted a failed invasion but what about when Ahmad Shah Massoud & Burhanuddin Rabbani took over Afghanistan (2 Tajik Islamists from Panjshir & Badakhshan who contributed to defeating the USSR), they didn't reject the Durand Line but what did Pakistan do?

instead of accepting a non-Pashtun led government in Afghanistan, Pakistan supported & nurtured the Afghan Pashtun Taliban vs Massoud & Rabbani & now the same Pakistanis are complaining when TTP (an offshoot of the Afghan Taliban) does suicide bombings in Pakistan, quiet literally you are getting a taste of your own medicine.

Pakistan's foreign policy is to keep Afghanistan as backwards as possible, that's why they installed the Taliban in Afghanistan in the 1st place, Pakistan hates the non-Pashtun people (Tajiks, Hazaras, Uzbeks etc) of Afghanistan so much that Pakistan would sacrifice their own civilians in TTP suicide bombings as long as it means non-Pashtuns in Afghanistan permanently suffer under the minority Pashtun gangster Taliban dictatorship.