What I don't understand is , Why do so many PCS subjects want to claim a diagnosis of PTSD?

It does not matter. Your current condition and symptoms are what they are. A label of PTSD means nothing. It just gives you an excuse for behaviors that may be choices.

After suffering a concussion that leaves you with long term symptoms and dysfunctions, the subject needs to learn to work with their symptoms, not deny them and refuse to change their life. Then the symptoms can be either minimized or otherwise accommodated.

Take the issue of anger and outbursts. The PCS sufferer needs to learn to recognize the triggers and be proactive in avoiding the triggers or walking away at the first sign of a trigger so the anger and outburst is avoided.

It requires a change in how you view life and others. An egotistical and selfish attitude of "I have a right to speak my mind" does nothing to improve or advance the situation. The outburst and anger is counter-productive to life.

The symptoms of PTSD are real, whether diagnosed or not. What matters is the patient does not rely on the diagnosis of PTSD to justify his behavior. Rather he chooses to acknowledge the complications in life causes by PTSD symptoms, and works to make changes in behavior and thought processes.

Gotta go to rehab.

Maybe more later.