As John Charmley puts it, Churchill was "terribly alarmed that giving the Indians home rule was going to lead to the downfall of the British Empire and the end of civilization." that could be the reason for many to see Churchill as Villain.
But for me its the handling of Bengal Famine which resulted in 3 Million lives of poor people of Bengal/India. Just a few ships of Rice/Grains could have saved many lives in British India.
Historian Madhusree Mukerjee, author of Churchill's Secret War, has described how Churchill's policies led food to be diverted out of India to be stockpiled for the war effort, while the citizens of British-controlled India were left to starve. As Mukerjee says, Churchill propagated the "social Darwinian pyramid that explains why famine could be tolerated in India while bread rationing was regarded as an intolerable deprivation in wartime Britain".