If you read the ENTIRE article, you'll note that parts were still selected on some basis of fiscal responsibility - the video card, for instance, is the 980Ti instead of the Titan X...
When you come 3 months late (this was written Nov 30, dude!), it's hard to be nitpicky about trivial differences - once your motherboard hits the 300-400 range, it's pretty hard to go wrong...
When you're going insanely extreme, it's easy to build a computer that's $50,000... but we wouldn't really be interested... $8,000 is still within the means of some people - or at least within their hoped for means - and thus makes for a better read.
If you want crazy - just go to one of the built-it-yourself websites and just click on "maximum" for everything.... if you want interesting... read this article