Question

why did ruling the countryside become necessity

Answer 1

The East India Company was made the Diwan of Bengal on 12 August 1765; by then Mughal Emperor Shah Alam II. Thus, the Company became of the chief financial administrator of the territory of Bengal.

The Company officials understood one important aspect of expanding their base in India. They understood the importance of those who had ruled the countryside in the past, and had enjoyed authority and prestige. The Company wanted to be careful not to annoy those people.

Answer 2

The Company understood that most Indians followed the profession of farming, and if it did not promote cultivation then they may not able to earn huge benefits. With this motive, Company originated the Permanent Settlement in 1793, where zamindars were demanded to obtain rent from farmers and pay incomes to the Company.  

Such type of plans was initiated because the company wanted to rule the countryside regions because these lands will give them greater profits because the amount zamindars had to pay to the Company was fixed irrespective of the problems like crop failure or climate obstacles.