Parvez and Ali suffer from intergenerational and cultural conflict. Parvez enjoys the material goods and freedom available in England. He is proud of his ability to provide for his family, buy Ali a computer, and send him to college. He is thrilled to live in a place where he can enter into friendships with women, drink alcohol, and eat pork.
Ali looks at his father and what he values with different eyes. He has lived his entire life in England and doesn't understand what true poverty is. He looks at his father and doesn't see someone enjoying the good life but someone who drinks too much and hangs out with prostitutes, someone who has been seduced and ruined by the undisciplined Western lifestyle.
Ali rejects his father's advice because he finds in his father the face of a person he does not want to become. He has no context for sympathizing with his father, because he doesn't understand his background. He feels very little sympathy for England because he feels the English despise the Pakistanis.
For Ali, Islam is an idealized faith that offers an austere purity and instills a sense of pride and discipline in him. It represents the rejection of everything he dislikes in his father.
Both men have points on their side: Parvez perhaps places too much value on material goods, but Ali is overly harsh in his judgments and living in an unrealistic dream world that allows him to throw away the education his father is offering him.