CynicalAhole :
Hmmm, wonder why the author didn't suggest moving to a linux-based OS? Many people that are still using XP are likely doing so because of either financial reasons or hardware limitations.
On the business side of thing, many factories, warehouses, etc. use PCs with custom software and hardware which is not compatible with newer versions of Windows or Linux. Even if the software and drivers are available, there may be licensing fees and downtime attached to the upgrade.
In my case, I have around 30k$ worth of academic software licenses tied to my old P4 running XP so I have no intention of messing with the OS on that PC and risk invalidating those licenses. That PC will run XP until it dies unless Microsoft offers to pay me 30k$ to update my old academic licenses to current retail ones.