This argument has been gone over many times. People are going to buy from the place with the best combo of price and service. For purchasing skis, local shops offer very advantages in service over online retailers, and online retailers are often much cheaper. Now, for something like bootfitting, the best combo of price and service might be a local shop, but not for most things - skis, bindings, outerwear, etc.
Not to mention lots of NS'ers work for backcountry, and backcountry gives discounts specifically to NS members...hardly a faceless corporation.