Hello! Sir Sayyid Ahmad Khan was an Islamist philosopher and a progressive Muslim author. He was the founder of the Anglo-Mohammedan Oriental College (later known as Aligarh Muslim University) and is widely credited as the father of the Two Nation theory for India. His most important work appears to be The Causes of the Indian Revolt. As a modernist Muslim, Sir Sayyid insisted that his fellow Muslims learn to reconcile their orthodox beliefs with the scientific and progressive ideas of the modern age.
So, in light of this, why did Sir Sayyid write The Causes of the Indian Revolt? The answer is that he wanted to highlight both British incompetence in governing India and the dissatisfaction of Hindus and Muslims as inclusive causes of the uprising. The modus operandi of the British government at the time was to place full blame on the Muslims alone. Here are the main reasons in greater detail:
1) The British regarded centuries of Muslim rule in India as an aberration (a departure from what is considered proper or normal). When the British took power in India, they isolated the government from any form of participation by the populace, both Hindu and Muslim. Neither group had any say in how their country was being run. The Muslim upper classes who had once held important positions in government were now marginalized by their British rulers; no Muslims were allowed to sit on the Legislative Council.
2) The British were high-handed and inflexible in their dealings with the native Indian population. Both Hindu and Muslim soldiers were equally disaffected with military policies originating from the colonial government.
3) With the advent of the East India Company, Christian missionaries were also allowed into India. Both Muslims and Hindus felt threatened by this new religion. After the great drought of 1837, many Christian missionaries took charge of Indian orphans in stricken areas. Their well-meaning ministry aroused the suspicion and enmity of Muslims and Hindus who believed that the Christians meant to convert them by first proselytizing among their children.
4) The Christians raised the issue that traditional practices such as suttee were immoral. In Sanskrit, suttee/sati directly translates as the "good or chaste wife." Popular in some Indian circles, a living wife would be expected to share the fate of her dead husband at the burning funeral pyre.
Also, with the phasing in of secular law, Sharia law was effectively replaced. Under both Islamic and Hindu law, anyone who left their religion would be punished by excommunication and loss of inheritance rights (Hindu) or subject to the death penalty (Muslim). The British passed the Caste Disabilities Removal Act which aimed to protect converts to Christianity from such punishment. However, this raised the ire of both Muslims and Hindus.
Please refer to the link below for further reading. Thanks for the question!