You are wrong about the history. In illahbad separate nation was not demanded but it was declared that Muslims and Hindus are different. Confederation was demanded within the same country. It was Nehru who pulled out from this agreement at the last minute. If he hadn't done so, Jinnah had agreed for federation under one country.
It was actually Nehru who became the reason of Indias division.
When Nehru changed his mind and refused confederation, then Jinnah declared that we will divide India.
Watch this small video if you don't believe.