Spoiler alert: they don't. Wrote a slightly longer rebuttal on Medium: <a href="https://medium.com/@sonyaellenmann/cmon-this-is-oversimplifying-197cf9ea3e60#.985lmv1h1" rel="nofollow">https://medium.com/@sonyaellenmann/cmon-this-is-oversimplify...</a>