Do you really need to stretch after working out

Today at Crossfit my coach told me I was not allowed to leave the gym until I stretched. I didn't think anything about it, its something I have heard all my life from gym teachers to volleyball coaches. But it got me to thinking, what is the reason we stretch after exercising. We have been told that stretching after working out prevents soreness and injury. After reading some recent articles, the clinical research shows that there is no evidence that stretching prevents muscle soreness or injury or enhance sports performance. "According to American College of Sports Medicine, Stretching before or after exercise does not reduce delayed onset muscle soreness or reduce injury in healthy adults." We know now that stretching is not going to help reduce soreness or prevent injury but its not completely useless. While you are weightlifting or running you contract your muscles so much that overtime they become a little shorter and can cause some stiffness. For exampl...