We did not demand Bengali as the only national language. We demanded both Bengali and Urdu. You guys were uneducated in Urdu back then. Most of the Punjabis and Pathans I have met speak their mother tongue when with their own people.That's what RAW intended. To deny us a common working language. Urdu isn't my first language either you know.
Urdu was native to only the Muhajir community because of its birthplace in Lukhnow/Delhi belt. A common language requires a common and intact land, you have to understand this. Even a small country like Switzerland with intact land has four national languages: German, French, Italian, and Rumantsch. Now, what are you going to do about that country? Impose Urdu upon it? English was supposed to be the common language of Pakistan and not Urdu.