Why should the schools have authority to call the parents if one is tardy to a class. Are we in prison or school?

If a student is late they call there parents. If a student is more than 10 minutes late which is an absence they call there parents. Why do they have to call every single day to the parents if one is late or absent. It is understandable if the student is missing class a lot they call but if it's once a while or one is tardy which is like 5 minutes late to class why do they call. It causes problems with the parents for a minor issue.