How, exactly, does the confiscation of food items serve the 'functions and goals' of the school? Are cauldrons blowing up in Potions class because of dropped crumbs? Are the telescopes in the Astronomy Tower getting smeared with jam?

It's not just the issue of the food. It's the relationships. My mother, as you know, has been recently widowed. Cooking and sending care packages to her children is one of the ways she's dealing with her grief. Do you really think it's politic for you to interfere with family relationships in this way?