Answer:
Public sector in india were once upon a time at commanding height of the economy. Due to its preeminence the first PM Nehru had called it the temple of modern India. But today ,barring a few exceptions, public sector in general is deteriorating at an alarming rate. The reason can be cited as below:
1. Monopolistic behavior: Public sector usually since independence operated without any competition from peers. This led them towards complacency
2.Inefficiency : Not facing challenges resulted into public sector being inefficient . Because they didn't have to be accountable.
3.Non professional management: Public sector usually is governed by generalists Ias who are not specialized in that field . They may not understand the nitty gritty of the underlying business model. More so these officials do not have a fixed tenure there . So by the time they try to learn the detail, they have to get ready for next department. In this way company becomes rudderless.
4.Deep nexus between Politician and civil servant: This result into misappropriation of public sectpr accounts profit. And very less profit is left to run the organization and to expand it.
Although the above reason is responsible for deterioration of public sector , but it is not rigid pattern . Once the good practices starts slide can be reversed. For example Isro Antrix , HAL etc is continuously making profit whereas Air India , PSB are in deep losses.