Bsnl's main cause of failure is its lazy/arrogant employees. When one complained it took a lot of time to act upon it and if reminded customer was simply chided off. There was too much of this 'chalta hai' attitude. Here is what the private players took advantage of. Their customers also had problems but they solved it quickly. Bsnl was cheap, network was OK but still went to loss, why? Because of its employees attitude who took their job for granted and did not paid any heed to customer satisfaction. And when they started improving they were way behind the rival companies like vodafone and airtel. And with arrival of jio to even these private players losed their customers.