While it might have seemed like a good idea for Sultan Singh to start an egg business, the population of India is largely vegetarian due to religious reasons and does not eat eggs so the business failed.
Step-by-step explanation:
Hot and Cold foods are described locally and known intuitively by many people who follow the Hindu religion. Eating habits are based on the demarcation.
Cold foods are not eaten after sunset as they induce cold and fever it is believed. These include curd, fruits and even rice which is served hot.
Any other type of staple food is believed to be hot and can be eaten throughout the day.
The Singh business did not run because of the strict eating habits of Hindu of which the above is a great example. These habits include not eating non vegetarian food on certain days for even the people who do. Thus a non vegetarian business finds it hard to function in a Hindu majority region.