200 million is a big number; as I said at the beginning of the article, 200 million equates to roughly one license for every 35 people on Earth. As your comments suggest, very few products are so widely spread. But it's not "insane" to call Windows 8's sales disappointing.
As the article elaborates, when Microsoft says "200 million," that doesn't mean 200 million customers have actually decided to upgrade to Windows 8 or 8.1. So in that sense, 200 million is not 200 million.
Moreover, if we look at the OEM numbers that enable Microsoft to claim 200 million, we find additional concerns. As the linked article is this story elaborates, reputable publications such as The Wall Street Journal have reported that Microsoft might have substantially slashed Windows and Office licenses fees in order to stimulate OEM production of ~8-inch Windows tablets. Admittedly, we don't know if this is true, but manufacturers produced a lot of smaller Windows tablets last fall, and most of them came with Office-- so that's at least circumstantial evidence than some behind-the-scenes dealing occurred. Certainly, key executives at many Windows OEMs were publicly criticizing Windows 8 throughout last spring and summer. The trash talk from Microsoft's alleged friends doesn't suggest many of them were eager to invest more in Windows 8 without some motivation. If we assume, for the sake of argument, that Microsoft did indeed reduce license costs, then the company is clearly earning less money on each Windows 8 license than it did on licenses for previous versions of Windows. If this tactic eventually stimulates Windows Store revenue, then perhaps Microsoft's gamble will end up paying off. But for the present, the Windows app ecosystem is problematic. All of this reinforces that 200 million Windows 8 sales are less valuable than 200 million sales of previous versions.
The preceding point is somewhat speculative, but turning back to verifiable facts, we know many early Windows 8 licenses were delivered at a discount. So again, some of the Windows 8/8.1 licenses are more valuable than others. This point doesn't rely on the OEM reports; if those reports are true, they'd simply exacerbate an objectively problematic situation. As I indicated above, it would be moot to talk about the relative value of different license types if Microsoft's various tactics had resulted in blockbuster device sales or stimulated developer interest in the Modern UI. But Microsoft has seen disappointing progress on these fronts. The company might still have some cards up its sleeve (stay tuned for Build in April), so the Live Tile interface might not be down for the count. But currently, Windows 8 has sold more slowly than Windows 7, and probably at lower margins. It also hasn't provided tangential benefits. In all ways, that sounds like a product line headed in the wrong direction.
To be clear, Microsoft is very strong overall. Outside of Windows 8, most things are going well. Azure, for example, could become for the cloud era broadly what Windows was to the PC era. But Windows has been a traditional cornerstone of the company's strategy, and no small part of the influence it's been able to wield among customers, competitors and partners. 200 million licenses might sound like a lot, and in certain ways it is-- but from a sales perspective, the OS hasn't lived up to its heritage. Some people say that Microsoft is doomed. That's ridiculous. But that doesn't mean that Microsoft isn't experiencing disruption, with Windows at the epicenter.