Complexity may be Windows' downfall, and Microsoft has not only failed to address the problem, but exacerbated it by shipping the dual-threat, two-UI Windows 8, analysts contended.

"Windows 8 is massively more complex [than its predecessors]," Ben Thompson, an independent analyst who covers technology from his Stratechery.com website, said in an interview. "It's mentally taxing to use, and a classic example of something borne of strategic need as opposed to an understanding of user needs."

Thompson's take on complexity, and Windows 8's place on the spectrum, started last week when he pondered why Google's Chrome OS, and the Chromebooks it spawned, had gained a small victory in the battle against still-dominant Windows-powered notebooks.

Although he acknowledged that Chromebooks' lower prices contributed to their rise, he also contended that simplicity played a part.

"The problem comes when you overshoot your customer's needs," Thompson wrote on Jan. 6 in a piece on his site. "In that case, it's not simply that the additional performance is not valued by your customers; rather, the bigger problem is that the additional complexity that necessarily accompanies said performance is actively harmful to your customer's user experience. Your product is not only becoming more expensive, but it's actually becoming worse from your customer's point-of-view."

Chromebooks dial back complexity

Enter Chromebooks, which were not only less expensive than an average Windows notebook, but relied on an operating system that was essentially just a browser.

"The new entrant may not have all of the required performance, but along with that missing performance comes additional simplicity," Thompson argued, talking about Chromebooks and iPads. "Paradoxically, the fact the new entrant has less-than-desired performance makes it even better from a user experience standpoint. And, when the performance gets close enough, that user experience advantage makes it an obvious choice over a higher-end product that does more, in every sense of the word."

Windows, because of its long life and Microsoft's dedication to supporting legacy software, has an inherent complexity that puts the OS at a disadvantage when pitted against less powerful, less capable rivals, including Chrome OS and Apple's iOS -- especially as users discovered that alternative devices like tablets met many of their computing needs with simpler solutions. As a result, sales of all-powerful, do-anything personal computers powered by Windows slowed.

"Windows is suffering from 'second-system syndrome,'" said Wes Miller of the research firm Directions on Microsoft, describing the tendency of successive iterations of any system -- in this case, an operating system -- to grow larger and more feature-laden to appeal to an ever-widening audience.

The term "software bloat" is sometimes used to describe the same phenomenon.

"That applies to [Apple's] OS X as well," said Miller.

Apple's choice in the war against complexity was to recognize that OS X should not be shoehorned into other devices; instead, it crafted the touch-based iOS as its standard bearer on first, iPhones, then iPads.