Shaming an adult is a sever punishment. It scars them in the public's eye for the rest of their life. Punishing a kid in 5th grade by using the media means that in sixth grade his new teacher is already going to know he's a bad seed, and he knows this. He's going to expect them to look at him disapprovingly and so he'll act like the bad kid they already think him to be (whether or not they do think that, its already in his mind that they do). It will be this way in every grade from now on, he can never have a clean slate... ever! Public embarrassment isn't a joke, and his teacher is clearly a jackass for doing this to him.
Shirt L
http://psychomar.deviantart.com/art/monkey-Airlines-120641302?q=boost%3Apopular+monkey+airlines&qo=4
http://www.channel101.com/shows/view.php?media_id=2224