I've found that this method of pulling quality writing out of my head works on the days when its toughest to get them out. Even I've written complete gibberish on some mornings, only to be hit with some amazingly creative stuff later that same day afternoon. To provide an analogy, it would seem that writing gibberish is the minds version of recreational running. Doing slow aerobic runs to build cardio strength for the anerobic sprint in the evening.
Also, like you already mentioned in another one of your articles, editing in the morning does help get the creative juices mixing, and your brain serves you up an article ready to be drafted by the evening. Some of my best work has been produced in the evening after an entire day spent editing, commenting on other posts, and writing gibberish. Along with a little bit of help from our dear friend caffeine as well, yeah.