The flaw in that reasoning is that even if he installed Linux or another OS, he still would have been paying for the Windows license. On the other hand, there have always been manufacturers selling PCs with no OS installed. On the third hand, no major OEM would dare to do this, since they fear retaliation by Microsoft.
Fair enough. But, as you pointed out he could've bought a computer from a dealer with no OS installed.
Everybody I know who is a Linux aficionado never buys a computer with Windows pre-installed. They either build the computer themselves or buy it from a dealer who sells PC's with no OS. I think the complainer in the article just wanted something for nothing.