My T has told me that it is a very creative way of coping. I've never once heard her say that dissociation is maladaptive. I'm still in earlier days of dealing with dissociation in therapy but if anything I'm always being told it is a creative skill I needed to adopt to survive- without it things could be much worse and I may not be as highly functioning as I am, if that makes sense. I'm sorry you are dealing with this in therapy, I can imagine how unsupportive it must feel.