There is a leadership book called "First Break all the Rules - What the World's Greatest Managers Do Differently". It's data driven by a large meta-survey and research project.
One of the conclusions was that, essentially, the normal instinct with Performance Management to focus on improving weaknesses is wrong and leads to sub-optimal outcomes. The best managers actually doubled down on each individuals strengths, and simply accepted weaknesses as something to be smoothed out to the minimally acceptable level. (e.g. someone may not be "good with people", but they can't be openly hostile with co-workers.) Instead the manager would look for another employee which had that weakness as a strength, and manage responsibilities appropriately.
It speaks exactly to what was wrong in OP's experience.