Not many brick and mortars cater to or focus on professionals. If you're on this forum, you're most likely past their target audience. It's now just as well with them that you (us) rely on the internet for what we need. They fill the need for a different segment (a large segment) of people who are very unsure of what they want and need direction. There are a number of ways to achieve an end and they will suggest to you the path they can, based upon what they have to offer at that time. They fill this need pretty well.
About a dozen years ago, I wandered into our local Rockler, on a lark. Up to that point in my life, I had had only intermittent woodworking experiences but always loved the idea of the 'field' in general. Junior High Shop Class had been a very fond memory. Over the next five or so years, I spent a lot of time in that Rockler. Built a garage shop and started making all sorts of 'stuff.' They were always there to answer my plebeian questions and to lead me along my path. I continued but after a while, I outgrew them, began needing (wanting) specific things which were harder and harder to reliably find there, for whatever reason. Their advice was no longer needed or very helpful because I had continued the passion to a level beyond their target audience. I still patronize them as much as possible because without them, I doubt that I would have been able to be where I am today.
Fast forward to today and due to a career change (read: family business), I now import exotic hardwoods from Central and South America and (single handedly) operate 12k square foot shop filled with old iron purchased from IRS auctions and hardwoods like Cocobolo and Ziricote. I cater to local custom furniture makers looking for something they can't find through the normal channels. It's a tough-go catering to such a specific (and SMALL) market and I fully understand why a chain would never make it doing so, however, it is because of their inability to do so that I have created a very small niche for myself.
I thank Rockler for my early years and regrettably have limited use for them anymore, even though I try whenever I can. I actually supply my hardwoods to our local Rockler and often think to myself of their significance in that fact. They're the ones enabling the 'next generation' to figure out if they want to continue their path or not. I'm guessing that next generation of woodworkers would be a much smaller one without brick and mortars such as Rockler and Woodcraft. So that's the way I see the function that they serve.