I have told a therapist they were doing therapy wrong for me, and then I left and found another who was not as wrong for me. I don't think therapy is specific enough to say that any of them are wrong in a vacuum. Even crystal growing and chakra cleansing seem to help some people. Who am I to say they are not helped by it just because it does not help me? I think the problem is that therapy is not science and a therapist develops something they think they can do and for some people it will often not be awful. For some it will be. I would have no problem telling a therapist they were doing their job wrong if all (or even most) could agree on how to do their job, which they do not. I certainly believe in telling the therapist they are doing their job wrong for me, but I don't think most are skilled enough or willing enough to change and so the quicker, better solution for me, is to find one I think does a better job.