Such a good question. I've wondered that too. Sometimes I've found myself getting prickly in a session - irritated that my easygoing, feel-good, incense-and-crystals therapist seems to think everyone should want to be the way he is. He was very up with people, thought I should be more positive, and was trying to help me get over my anger. He
really didn't like my anger.
The problem was that I didn't WANT to get over it. I can't say that I like being angry, but it's part of who I am. Some things happened to me as a kid that shouldn't have, and forty-some years later, I'm still pissed off about it.
This anger isn't just an inconvenient symptom of my failed life strategies. It's really important! My anger is a reminder of the source of the wound, and I mustn't ever lose sight of it. That wound is who I am, just like my physical scars have become a part of me, and they're a reminder of my experience, the things that have shaped me for better and worse
Also, anger can be revealing. It can revive memories, reveal sources, inspire insights about our deepest selves.
Anyway, life is light and dark. And we need the dark - we need the shadow. We need it all!