The results of the mentioned study are very interesting but regardless my opinion falls on the side which feels stretching is beneficial. I feel it is less of a possibility to injure a body part that is warmed up, flexible and ready to go. Stretching also helps to get one in the right mindset for the upcoming physical activity.
I was told long ago that stretching before you exercised was a waste of time, that you got marginally more benefit from stretching after, when the body is warmed up. But everyone should try to have a period of time before and after exercise when they are getting into (or out of) the right head-space, leaving the job or kids behind for a few minutes, concentrating on the movements of their body. If stretching accomplishes this, it's beneficial -- even if it doesn't decrease the injury rate. The folks who stretched only some of the time are probably rushed, and aren't getting themselves fully into the exercise head-space.
There has been a lot of back-and-forth over the years about stretching. I think that with any physical activity, even something as simple as stretching, it is important to have good form and to know when and how to do it. Some people push themselves too hard into positions that can cause injury. If people do not ease into it, it can do more harm than good.
Stretching is something that most people do before a workout to loosen up. I am unsure if there is any proof that it reduces injury, but it does help a person get ready to run. It's just like waking up in the morning - most of us stretch out when we first awake in order to start moving for the day.