The reasons behind the lull between the first and the second waves were not entirely clear, and some people assumed that the herd immunity is being reached. Combined with the desire to return to normalcy after a harsh lockdown, it falsely assured people that the worst was behind them. This created the perfect conditions for a bigger second wave.
Finally, the state and every petty official was intoxicated by the powers they weilded during the first lockdown, and they forgot that with great power comes the great responsibility. They unnecessarily focused on tiny things such as fining people Rs. 500 at the traffic lights, while not really understanding the new information on how virus spreads, what are the best ways to tackle transmission and so on. People should have been given the liberty to be outdoors with proper face covering when there was good airflow. They shpuld have known that meeting indoors with poor airflow was the biggest threat. This wasn't communicated properly.
Some government officials did take decisions proactively to save their own district. For example, see here
But unfortunately, this was the exception rather than the norm.