Organization and simplicity share a piece of the same spectrum. Simplifying our lives is the notion that it makes sense for us to pare down the activities and stuff that we cram into our lives, and focus instead on just those parts of life that truly matter to us, whether that means our kids, our partners, a wonderful career, volunteer work in Kenya or a hobby making model airplanes. Organization is economical. When you are organized, you don't have to buy duplicates, you don't lose, break or ruin quite so many belongings, you have the time and inclination to repair things when they do break, ravel and come unglued, and you don't feel the need to drown your disorganized sorrows with an evening at the mall. Frugality doesn't have much to do with how much money you have, only with your attitude toward that cash.
Organization is good for the environment.
For many of the same reasons that organization is frugal, it's environmentally friendly, too.