My opinion on lunch detentions

Detentions in my mind don't actually make a student more well behaved, I've gotten one lunch detention for drinking water (not joking). I had to sit at a table at the front of my schools cafeteria. The detention lasted the whole lunch time and a little beyond, because I had to stay and clean tables even after the bell had rung. After the detention, I had thought about why they hand out these types of detentions. In my opinion they do these detention because they think that humiliation and labor (that should be reserved for janitors) will help make the student a better person.