When a Punjabi kid gets education, he is uprooted from his soil, family and the roots. When he goes to school, he learns that his own language and culture is inferior to the Ganga Jamni culture and language. He carries this inferiority complex for his whole academic career as he is not allowed to speak Punjabi at any formal forum. After getting married, he and his wife decide that they would speak Urdu with their kids so that their new generation should not face the humility that they faced themselves.
So they forbid their kids to mingle with their grandparents and the cousins living in village who speak Punjabi. This way, they get totally disconnected not only from their soil and society but also from their very close family and relatives.
And this is worst of imperialism!