Over half of the world population own a smart phone already, that's billions of people. This also doesn't include people who own a tablet if their tablet has a built in camera, and often times people with a table have a cover/foldable prop up. A stand/prop up for a phone is significantly cheaper than any dedicated web cam ($10 or less), and often times, even if it's not a flagship phone, the camera on a phone is much better than the cheapest of webcams to compare to the cost of a stand/prop up.
There is nothing wrong with this article pitching this idea for anyone who finds it suitable to their circumstance, needs/wants to have at least some method of video conferencing while at their desktop. Especially for anyone who just doesn't want to make that extra investment into a decent/quality webcam.