When I worked at the Apple Online Store, almost a decade ago, it fell under Apple's Engineering department. More specifically, the online store fell under Eddy Cue who also oversaw the iTunes Music Store, as it was originally called since it initially only sold music. That changed, about half a dozen years ago, when the online store moved out from Engineering, into Apple's IT department (IS&T).
Of course you can still buy Apple hotness at apple.com, but there isn't a separate tab for the store. Instead, you add items to your shopping bag, directly from a product's marketing page.
I've always enjoyed telling people about my experience at the Apple Online Store. Before each of Steve Jobs's Keynote speeches, we'd turn off the store then Steve Jobs would take the stage and announce the new products we, the store software engineers, didn't even know about. After he walked off stage we'd turn the store back on under a huge load. Most customers would skip the marketing pages for the new projects and immediately go to the online store and add the new products to their cart to see the prices, configurations, and order ship times. I learned some important load balancing and stress testing lessons while working at the Apple Online Store, especially for scaling servers and writing fault tolerant code.
Does this change make sense? Of course. Looking back, I ask myself why it wasn't this simple in the first place. Probably because this was how it was done in the 1990s. Now, without an explicit store, each product's marketing page is where you browse and the shopping bag has become the checkout portion of the old online store. At first, I was wondering where I'd find accessories. It turns out those are under each of the respective product tabs (Mac, iPad, iPhone, and Watch). So, it all works out. As Apple grows bigger and bigger, streamlining and simplifying processes pays the company dividends.