Mr. Varma wants to die because he feels that his quality of life is deteriorating.
Mr. Varma was so proud of his "devoted son." He believed in the praise that others had heaped on him regarding the filial love that Rakesh showered on his parents. However, as Mr. Varma's health worsens, his son takes a more defining role in monitoring his diet. His joys are now limited by Rakesh, who is devoted to his father's health: “No more halwa for you, papa. We must be sensible, at your age. If you must have something sweet, Veena will cook you a little kheer, that’s light, just a little rice and milk. But nothing fried, nothing rich. We can’t have this happening again.” From this point, Rakesh gives his father tonics, pills, and limits the eating of sweets and savories once enjoyed.
As Rakesh takes firm control in his father's diet, Mr. Varma feels worse with each passing day: “Deprived of food,' screamed the old man on the bed, 'his wishes ignored, taunted by his daughter-in-law, laughed at by his grandchildren—that is how I live.” This becomes the motivation behind why he wants to die. He feels that life is not worth living if he cannot enjoy the small things in his life. At the same time, he feels that his son has turned into a force that "deprives" him of what he wants when he wants it.
Mr. Varma is thus possessed by two forces that make him want to die. The first is being denied that which he wants at his particular stage in life. The second is being denied at the hands of a son that he believed was so devoted to him. Both forces help him feel that he no longer wants to live.