A lot of the article wants to point the blame at Windows 8. This is a contributing factor, but look at it that way, Windows ME and Vista both have/had some very serious negative feedback, did PC sales drop that much then because of word of mouth? However, many other factors play into this, mobile phones are on the rise, Dell/HP shakeup, poor PC designs, and the biggest thing of all, I think its partly due to less people needing to upgrade their current computer. PCs these days are not upgraded to new ones as often because the hardware specs are good enough now. This all can't be about Windows 8, look at the whole picture.
Me and Vista were not in the situation where the market is at this time. Apple is a major influence when we look at their offerings and their sales. They've sold more Macs than in any other quarter in the worst economic climate. Me and Vista were in periods before the economic collapse where people were consumers at their peak in technology adoption.
Everyone was buying computers and getting involved. As stated earlier, phones act in place of the PC for basic function on the web. Windows 8 was not well recieved and has a stigma that is Metro. Compared to 8, Vista never forced users to "adapt" to functionality that wasn't necessary.
Microsoft acted out of impulse because of the success of Apple's iPad and they thought they could wrap around an interface for all devices by hitting multiple targets with one stone.
The sales reflect the outcome.