Why did british rule start to come to an end during the 1940's

 the British reaction to Amritsar – the officer commanding British troops at Amritsar, General Dyer, was simply allowed to resign his commission after an inquiry criticised his leadership during the riot. Many national Indians felt that he, and others in the army, had got away very lightly. The more radical Indians felt that the British government had all but sanctioned murder. 

Answerleveling;

Largely uneconomic because they provide little profit or food surplusi think so