I don't think Apple is abandoning the pro market. I just think the pro market is a steadily shrinking piece of the overall computing pie and Apple is responding accordingly. With the both the massive growth of mobile—Apple surpassed one billion active iOS installs last quarter and we're seeing double digit YOY mobile growth in China and India—and the steadily declining sales of desktop machines, the pro market is slowly, and steadily, transforming into a niche market. Most people don't need more than 4 cores (real, or HT) or workstation-level GPUs.
I remember when you needed G4 or G5 to get any serious work done. Now, a Mac Mini can handle anything Adobe can throw at it outside of serious Photoshop work and After Effects/Premiere, and a five-year old MacBook is more than enough for every day computing needs. I know professionals who spend almost of their outside work computer time on their phone or tablet. They do web browsing/shopping, email, Netflix and casual gaming just fine. If they need to run Excel or Word, they have a laptop, but that's about it. I know professional photographers who run their business on 13-inch MacBook Pros. I know kids who only use laptops for writing papers or Minecraft.
In short, commodity hardware has finally caught up with every day computing needs, pushing those who need more to the edges of the computing market. It's even happening in the gaming world. Asus and others will sell you a laptop with an i7 and a full desktop 980. For ~US$500, I can build you a PC which will run GTAV at 60 fps all day with no need for an 8-core i7 or a 980Ti.
While I have a 2010 Mac Pro, if I'm honest, I could probably survive just fine with a Mac Mini. I have an i7/GTX 980 PC for gaming, an iPhone and an iPad. The Mini could easily take care of any day-to-day stuff, and it runs InDesign/Illustrator/Photoshop and friends just fine. I love my Mac Pro, and I've had fun upgrading it, running VMs and generally screwing around, but my next machine will likely be a MBP.
I think Apple is simply responding as the market is changing. It reminds me of watching the decline of the workstation market in the 90s. When I was in school, from the late 80s to the early 90s, you needed a DEC, Sun or a NeXT to get anything serious done. Ten years later the massive increases in performance, and drop in cost, resulting from AMD's challenging of Intel's CPU dominance, coupled with the emergence of Linux, meant you could build a desktop machine as fast, or faster, than a $40,000 workstation for 1/10th the cost. And, if you remember, all those workstation makers went out of business very quickly (or, in NeXT's case, were acquired by Apple).
None of this addresses the frustration and anger of watching Apple's focus shift from its traditional base of creative professionals to a wider audience. And, obviously, none of this addresses people with thousands and thousands of dollars, and many years of experience, invested in an operating and ecosystem who must now think about switching away from their preferred platform. But I think it does address the idea that Apple has shifted focus away from serious desktop machine because it's more interested in making shiny toys. iPhones and iPads are no more toys than Apple's early 90s consumer machines were compared to a fully loaded NeXT Cube. They're simply where computing is headed, whether we like it or not.
