I understand. I should put a caveat here: I haven't read the entire thread. I have very little structure in my life anymore and my sleep patterns are abnormal so I don't get much of the morning blues anymore. My morning blues were usually caused by watching the light creep in as the sun rose after yet another sleepless night.
At other times in my life it was just the prospect of facing a new day. That may have been attributable to a negative attitude... the result of too many previous days of sheer crappiness.
Mornings are beginnings. A time of expectations. Demands to be met. Those are very difficult situations seen through the lens of depression.