I felt the same way. I thought it was about weakness of character, but that's because we expect them to react to things the way we do, but they don't. Without validation, in the face of moderate levels of continuous stress, they just can't take it.
Under stress, they want to tend and befriend, not fight or flight. However, when their children become less dependent, and they are unable to "befriend" due to work responsibilities, etc., they can't manage stress. I've come to the conclusion that my W definitely is behaving as if she has PTSD, which explains a lot and is consistent with the works of Grey, etc.
