The original Harpers magazine said:

We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganized. Presumably the plans for our employment were being changed. I was to learn later in life that, perhaps because we are so good at organizing, we tend as a nation to meet any new situation by reorganizing; and a wonderful method it can be for creating the Illusion of progress while producing confusion, inefficiency, and demoralization.

Note that the oft quoted text has fewer words and has been edited for more impact, (the original only applied to a nation) suggesting that Harpers was the origin. (it is unlikely that the extra words would have been added to a known quote) A shame, I liked the idea it was a universal truth. But I'm not going to let the truth get in the way and will continue to ascribe it to Petronius.