In what way would it have been awful? Even if you shifted schools several hours ahead of your wake time, it just means that you have more time in the morning and less time in the afternoon, but still well within your normal hours.

I think the goal of these sorts of policies is to increase the breadth of students which can benefit from you know, actually being well rested inside school hours. A person that sleeps later and wakes up later (which studies that justify these sorts of policies indicates teenagers largely are) would benefit from a later start time.