There were many reasons, they were more politically aware. After all Punjabi was also sacrificed which at that time was the second largest language. Their population was larger than west Pakistan, there was no land link. When the majority would have decided they would have seceded. I have never supported the high handed tactics by Pakistani army in that conflict. However I feel that we look at the conflict only from one direction, we don’t know what happened from the other side. The figures of casualties like I mentioned are highly inflated.