They may cary them, but they don't make them. I've never had an ussue with any case I chose on any phone I've owned. Also, Samsung can't be expected to carry ever color/design of a case for every model they make. For that you have to search online. Samsung shop probably only carries the most popular colors and styles. Also, th OP was no lamenting the lack if cases at Samsung shop, only that it's easier to find jPhone cases at retail, as opposed to Samsung.
As with any retail outlet, stores decide what inventory they will stock, as shelf space is limited. It's easier to stock a variety of iPhone cases, because Apple basically has one new model per year, not 3 different versions of 6 different models.
