How we got here is not as important as where we are going.

You can’t change the past, but you can improve the future. Too many people obsess over the past. They want to document everything that happened, create an official record. The problem is, you can’t change the past. It’s already happened. At best, you can color the recorded history, so that when other people look at it, their opinion may be slanted the way you prefer. This borders on being dishonest or misleading, which is not a good thing. And most of that energy is wasted, as few people are interested in the history. What really matters is where things are headed in the future.
Determining blame can be a waste of time. Instead, develop a plan to move forward. If people are focused on blame, they aren’t working towards making things better. They aren’t moving in the right direction. People who pick up the dropped ball and carry it forward are the real heroes.
Now, one agile practice is to pause and reflect upon the past. Having retrospective meetings are only good if they lead to future change. If you find the retrospectives become just another ceremony and don’t result in changes, then they aren’t doing any good. To avoid wasting precious time in yet another meeting, ensure that each retrospective results in changes to processes.
Look to the future. That’s where we’re headed. Preparing for a better future is infinitely more productive than whining about the past.