Like so many others, scans have increased my interest in buying magazines, so I don't consider the content I find here to be harmful to the industry. When someone posts images of the new Vogue Paris, it merely incites my interest in getting my hands on the actual (and rather expensive) issue. For anyone who loves magazines, scans are always going to be a secondary resource to the need each month for the physical product. A useful resource, but secondary nonetheless.
What stops me buying magazines is the endless recycling of uninspired content, which starts and stops with the magazines themselves, it has nothing to do with scanning.
That said, could it be argued that being exposed to a greater selection of the content of magazines, thanks to scanning, has increased this feeling for me? Well, the existence of the internet has led me to becoming overly saturated with information of every sort, you can't single out devoted scanners as the people who have created the overload. Or more precisely, companies will try to do that, because it's easier to get legal with a few individuals than it is to get their business heads around the seemingly uncontrollable universe of impulses and patterns that is the internet.