I agree with you that diagnosis facilitates insurance reimbursement, and I am not thinking of diagnosis as a negative concept, although I think the system has room for much improvement.

Maybe my thoughts are tangential to the conversation because I am looking at the big picture implications, but these diagnoses are used for research also and so they are used in formulating evidence based treatments and research funding and policy making, to name a few. The stakes are high, so in my opinion, this diagnostic system can't afford the extremely low inter-rater reliability that exists with the current system.

The DSM is based on descriptive symptoms, which doesn't align with psychodynamic thinking. For example, the behavioral symptoms often point to extraversion, rather than the internal world of someone suffering from BPD, so introverts are often excluded from the diagnosis (often given the Bipolar II diagnosis). People with BPD can express their symptoms in many different ways, but the nature of a descriptive diagnosis limits the diagnosis to only people who express the disorder through the narrow list of symptoms listed. But despite that, DBT was created. If Linehan was not suffering from BPD herself, this treatment may have not been conceptualized. Who really knows.

It just doesn't match with psychodynamic conceptualization, but then the CBT promoters complain that psychodynamic therapy is not "evidence-based". Well this is one major reason why. Of course CBT can be researched to show more evidence because the symptoms align with the diagnosis system in the first place. There are other problems with the research....but what happened is that people in the UK and elsewhere are extremely limited in the treatments they can receive as an indirect result of this diagnostic system.

So it can be damaging and so some of us might like to discuss or promote awareness and trends for potential improvements to the overall system.