For me it’s not the branding, but reliability.
In my personal experience, my Apple systems have been significantly more reliable than the Windows workstations I use on the job. There have been a number of times where I’ve brought work home or my computer into the office, to solve a problem we’ve had on otherwise more powerful workstations. Sure I can build a faster computer for the same price. I can build a cheaper computer for the same speed. But my time is valuable, and a 20% speed gain is completely useless when you lose an hour of work to a bug, or a render fails at the 98% mark.
A Hackintosh can give me the OS elegance and compatability, sure, but there is no way I can guarantee what the reliability is going to be like until I actually do it. There’s also all the time that goes into researching the parts, comparison shopping and researching the methods for getting the OS to work properly, something that can be undone at every patch, while one of the niceties of my Mac experience has been the painless upgrades.
My last two Apple purchases have been 5-year investments. I expect this to be the same. The last two were a Cube and a 1st gen Intel iMac, so no, I’m not worried about overheating.
Simply put, you are completely right that you can get better benchmarks for the buck with a hackintosh. I wish you the best, and I hope that Apple releases a version of the OS for the homebrew market. My personal experience, however, has been that the Apple Premium over that length of time pays for itself in both the tangible savings of time from that reliability, and in the intangibility of a stress-free experience.