Are we not discussing the problems detailed in the first post? Please don't twist the point. I'm not dismissing the value of a diagnosis for kids who truly need it. In fact, I'm trying to preserve the difference between "need" and "convenient". We have been moving in this direction for the last decade and this DMDD is many of those worst fears come to life. That's exactly the point.
I can tell you from the families who have struggled with a child out of control (far beyond the description in your first post, mind you), having a diagnosis and knowing treatment options is often akin to the cancer patient hearing the word "remission". It's huge, monumental. Yes, it's a "label", but in more cases than not, that label then allows for progress to be made in order to allow the person to live the life they were created to live.