To me, it would make a lot of sense to be angry about being chronically dismissed and not receiving individual recognition (except for bad things). I have no personal experience with significant dissociation but if these personas have their own sense of identity, it is probably just as frustrating not to be recognized and respected as an individual, regardless of the physical reality of it (one body). And since the therapist is expected to be the one rare person to actually know about all this, of course it is maddening when she is confused and dismisses things. To me, that alone could be enough, being angry with her, not even necessarily projected or transferred frustration, although I guess the latter is likely part of it, too. I agree with others that it may be a good idea to talk to the T more about all this, maybe that way she would learn how to recognize and acknowledge the different identities better. Anyhow, I just wanted to express that I easily understand the intense anger and don't actually think it is exaggerated or out of place given the situation. I easily get how that would lead to thinking therapy is not useful.

I had a T in the past who was very bad at recognizing and handling individual differences even just between different people, very very dogmatic and projecting things all the time. It was infuriating and useless "therapy" for me as the analyses and potential solutions offered were not relevant to me and my history at all.