I'm sure that there are extreme cases which require correction in the form of special shoes, but the conclusion of the scientists they interviewed was that for the overwhelming majority of people it is distance, intensity and running style that are the major predictors of injury and not the type of shoe.
Do you run heel or toe strike?
Heel (mostly) and I over-pronate......motion control shoes have really helped me with running. My point is more that these things often end up making a valid point but over emphasising one side to hit home the message......of course lots of £s are drawn by the marketing men for stuff folk don't need but equally there are some great products that really do provide benefit. Re the bit about distance, intensity and running style being the major predictors of injury, then of course there's no argument with that. The sublety (for me anyway) is not making the case that trainers in themselves cause injuries but that for many trainers can prevent them (i.e. mitigate certain running styles that would otherwise cause injury over distance and/or running at a certain intensity).