Well it turns out that security is getting set up in other layers but these are for more specialized applications than general run of the mill internet usage.

Well it turns out that security is getting set up in other layers but these are for more specialized applications than general run of the mill internet usage. For example there is encryption available at the physical layer even at very high data rates. Additionally there is MacSec which is a layer 2 technology. It's curious that the author mentions neither.