Why do colleges expect high school kids to be super active / volunteering / working / extra educating...?

College is a big transition and when applications are being considered the college wants students who are well-rounded which shows the admission office the student is capable of handling different responsibilities simultaneously without being overwhelmed. The college first of all does not want to set anyone up for failure, not only for the student's sake, but for the college itself that wants to have the reputation of producing mature, intelligent, and successful professionals who can survive the demands of working and living.