I'm a proponent of grades. You'd have to be atrocious to continuously receive a bad grade, but it helps weed out the shoppers who "phone it in."
Please don't feed the MSF trolls!
Feeding the MSF trolls bread or other human food is detrimental to their health and the environment. It can lead to malnutrition, disease, and behavioral problems in trolls, as well as water pollution and the spread of pests. Trolls are capable of finding their own food sources and don't require human assistance.