Agreed on Six Sigma. I also worked at a major defense contractor for awhile and Six Sigma was a blight on us all. Not only did it cause the problems you listed but we also wasted so many hours from required "quality meetings" every week.
I picked up a book on it many years ago. The first chapter talked about needing to attack anyone that believe in six sigma, as in make an example out of them.
Realized it was a cult mentality and avoided working for anyplace that used it.
Oh god. Kill me with a spoon. I’d buried those meetings in a secret space in my mind along with all the other horrible things that happened in my life.