The author's point seems to be: "It's not that they don't know it's bad. They know, and they do it anyway. The fact that they know shows they're not stupid." U

The author's point seems to be: "It's not that they don't know it's bad. They know, and they do it anyway. The fact that they know shows they're not stupid." Umm, OK? I still don't get why, in the author's view, they do the bad thing on purpose, and why that is not stupid. (Perhaps the author might make say that doing a stupid thing doesn't make someone a stupid person, or something to that effect -- but, even if so, I don't see any sign of that argument in TFA.)