Exactly. You don't have to buy their products in order to eat low-carb. People who confuse the two don't know what they are talking about. Atkins is a way of eating, not a product-based service like Jenny Craig.
That's my biggest problem with "programs" like Jenny Craig or Nutrisystem -- by using their pre-packed stuff, you never learn how to cook properly for yourself, so it becomes that much harder to maintain the weight loss when you go off-plan.