I have not been fortunate enough to work on a team that did retrospectives. There were normally a few of us who wanted to, but it never happened. I was one of those who wanted to learn from what we did, when working on a big problem, but it never happened. Perhaps the manager thought about it. Perhaps it was just the need to start the next thing.
On the other hand, I've never been a part of a "ship party" whenever we released anything. My experience has always been, "OK, you got project A done; now onto project B." Perhaps the same thought processes are in play, if no one either celebrates a win nor spends any time learning from overcoming a huge challenge?
Kindest Regards, Rod Connect with me on LinkedIn.