See, this is where I think your particular niche (PC gaming) is causing you to project a bit onto the userbase at large. A big part of the reason why tablets are so popular is because the things a desktop can do were becoming an ever larger superset of the things most users actually need a computer for. Only a tiny percentage of all PC users actually play processor-intensive games on their computer. The vast majority surf the web, watch a bit of youtube, and check their social networks. These are lightweight tasks, and tasks for which a computer can last 10 years performing admirably.
At most price points (except yours, the high-end tower price point), Apple has a slightly more expensive option that is less frustrating and more stable, with some luxury features (like their industrial design and high-quality parts) that make people feel good about spending the little bit extra. It's a very squishy, touchy-feely set of reasons that a spec-head doesn't really accept, and that's cool; these are not computers for you. You have specific needs, and you're never going to be well-served by Apple.
I have some anecdotes, of course, but the one that sticks out is my dad. Before the company he works for became an Apple supplier, he switched to Mac. He had been living with a series of shitty $400 eMachines for the last 10 years (one every other year, like clockwork when the power supply blows out), and I suggested he blow an extra $200 and get a Mac Mini (with the better processor option). He eventually took my advice when a driver conflict on XP basically fragged his system.
Since then, he's owned one Mac Mini, now 4 years old. It runs without issue, quietly, acting as his scanning station, e-mail client, light photoshop tool, etc. It's never failed on hardware, and the only time he restarts is when an OS upgrade happens. He used to worry about not having a CD-ROM drive, but I told him if he had a need for one, I'd spring for the external drive. I haven't had to, because lo and behold, he's actually had no need for it. Heck, even Quicken, the one program he couldn't readily replace moving from PC to Mac, was superseded by my mom's iPad 1 (nearly three years old), which she uses to surf the web during the day and apparently keep track of their checkbook. These devices will be upgraded eventually, probably next year for the iPad and after two or three more years for the Mac Mini.
Yes, technology is growing faster, especially in certain spaces like devices. And you are poorly served by Apple's options (the horrifically overprices Mac Pro), but I think maybe you forget that your needs are not representative of the larger whole. Stability and safety trump speed and cutting-edge tech in many situations.
Think of Macs as Volvos. You need a Veyron. The only thing the two cars have in common is the letter V.
