Thing is, once independence became certain, peaceniks like Gandhi and others were politely ignored, as everyone was more focused on ensuring that the 500 odd kingdoms that made up India did not splinter away. Keeping the foucs on integrating these princely states as a higher priority, Nehru and Patel (India's first Home Minister, known as the Iron Man of India) were more concerned with Indian Integration, than with partition. Perhaps, they just thought that with the partition, Jinnah would be focused on setting up his nation more than anything else, and leave them in peace.
This backfired splendidly, as the issue of Kashmir propped up like a wart, which has still not gone away to date. The assasination of Gandhi did not help matters either. Most of the princely states acceded to Indian unification, but the Nizam of Hyderabad refused, and Patel gave the order for the newly formed Indian Army to move in and force its accession. Same thing happened with Goa, which was still in the hands of the Portugese, who refused to give it up. Again, the Indian Military forced it to happen at gunpoint.
By the time everything had stabilized to a point, too much blood had been shed, to give peace a meaningful chance. Basically, the leaders at the time were ill prepared to handle the transition to independence, and it showed in the way partition was handled. The titanic ego's of the politician's involved like Nehru and Jinnah did not help much as well.