Yeah, cause it's just that easy. Here's what the principal will say. "The school day is very structured and every possible measure has already been taken for the children to have as much time as possible to eat. But when you have X amount of time and X amount of students corners have to be cut somewhere. Blah blah blah."If you truely have a problem with the amount of time students are given for lunch, then you should talk with the principal of the school.
Most schools are more worried about test scores and funding than the actual students.