Have you interacted with Afghans ? They all hate us, well save for "ate main namak ke baraber" few.
Let me quote for you an excerpt from Mullah Zaeef's Tome "My Life with the Taliban" (Mullah Zaeef was the Afghan ambassador to Pakistan under the Taliban regime):
¡°Pakistanis can get milk even from a bull. They have two tongues in one mouth, and two faces on one head so they can speak everybody¡¯s language; they use everybody, deceive everybody. They deceive the Arabs by using the name of Islam, they milk America in war against terrorism and they have been deceiving Pakistanis in the name of Kashmiris, but behind the curtain they have been betraying everyone".
I would also encourage you to watch Afghan talk shows - The Pashtun participants are often more visceral in their hatred than the non-Pashtoon - this is subjective I know, but I assure you there is no real order of magnitude difference.