What did Ambedkar write about Pakistan, and why is it quoted by everybody?
In 1940 he published a long, cold-eyed study of the demand for Pakistan, expanded in 1945 into Pakistan or the Partition of India. It is quoted by almost everyone in later arguments precisely because it refuses to take the side any of them want. He neither cheered the demand nor dismissed it; he examined it the way an economist examines a proposal, weighing whether Hindus and Muslims had become two peoples who could not share one state, and what separation would cost against what forced union would cost.
That is why the book is mined selectively. One side quotes his hard passages on the difficulty of Hindu-Muslim unity and his warnings about the two-nation idea; another quotes his insistence that if a settled majority genuinely wanted to separate, forcing it to stay would poison the state that resulted. He followed the logic wherever it led, including to uncomfortable places such as a candid discussion of exchanging populations, and he declined to tie the threads into the slogan any faction would prefer.
Read whole rather than in fragments, it is a characteristic performance: a man applying reason to the most inflamed question of his day and refusing to flatter anyone's certainty. In the end he analysed Pakistan more rigorously than most of its supporters or opponents and committed to neither camp's conclusion — which is exactly what makes him quotable by both.