I am sorry your work has been frustrating.
Here I was talking specifically about code reviews, so the context is pretty different than an incident retro. A code review where there is nothing nice to say is probably not going to merge into the code base: it is going to get updated to address the issues, and then there will be something nice to say as I give it a plus one.
But when I run retrospectives, even in the most horrific cases we have a section on "what went right". Sometimes the answer is "nothing", but usually there is something that was helpful: a log message that helped us find the root cause, documentation that meant we didn't have to call someone, alerting that found the problem, a feature flag we could toggle off until it got fixed.
In a corporation, we are playing a repeated game. It isn't about just this one incident: it is about what all the people watching the retrospective are going to built tomorrow, and the day after that, and the day after that. I want people to hear what went right with this incident so they put the log statements & feature flags into their own stuff. Those are the kinds of things that may only be relevant when something goes really wrong, and it's easier to leave them off, so every bit of positive reinforcement we can manage makes our lives easier when we do get paged.