Why did Gandhi's argument failed to persuade the Viceroy to change the conditions imposed on the Indian people?

Gandhi's argument failed to persuade the Viceroy because Gandhi's proposal threatened him with disobeying the "Salt Laws," or Britain's Salt Act of 1882. Although the Viceroy (Irwin) was a religious person, he needed to arrest Gandhi and the other Indian leaders.

Explanation:

The "Salt Laws" prohibited the Indians from getting salt from the ocean (Indian Ocean). They have to buy the mineral from the British rulers, which means they will be buying the salt with hefty tax. This is the reason why Gandhi decided to do the "satyagraha" or "non-violent resistance" for the Indian Independence movement.

Gandhi first sent a letter to the Viceroy on March 2, 1930 about changing the conditions of the Indian people. However, the Viceroy didn't do anything thus, Gandhi and 78 other people decided to start the "Salt March" on March 12. This march was a hundred miles walk towards the seacoast of the Indian Ocean. Upon reaching their destination, they took a pinch of salt from the sea. Many people followed this march even after Gandhi was arrested.