Fashion Frustration

Why is it that in the 6 or so months that I was wearing and buying maternity clothes, the fashion industry decided to change their sizing structure so that now, I suddenly only fit into clothing that's approximately 4 sizes bigger than my old, pre-pregnancy size? I'm also upset that this new sizing structure effected my old clothes that were hanging, innocently in my closet during my pregnancy. Did some Fashionista Secret Agent sneak into my closet and alter my old clothes to conform to the new sizing? How did I miss all of this? Grrr....