Well we cant say this for every Pakhtoon, for many I have interacted with were perhaps more patriotic than I am. However, let me share a very strange incident with you.
In December, I was in Islamabad to sign some MOA with a local University. The VC of the University has been my Mentor during my University days in Quetta. We have almost 20 years long extremely cordial relationship. I was invited at his place for a dinner and many of his family members were there too. His family is highly educated and extremely well to do. One of his very close family member is serving as a Lt. Commander in the Navy. During the talk, that Lt. Commander started ridiculing Pakistan and said that the Durand line is dividing the Pukhtoons. I just could not believe my ears that a serving Navy Lt. Commander could say something like this. He went on (literally boasting) saying that I slapped my 4 years old kid for speaking in Urdu, for I want him to speak in Pushto. What? Of-course all this conversation was in Pushto but it didn't really get down my throat.
This is very disturbing trend and I am away of Pakistan for almost 15 years now. Is this a wide spread phenomena among Pakistani Pakhtoons, I hope not.