Answer:
The most convincing argument to support this cause is scientific. Teenagers have a natural tendency to stay awake until late at night because their brains secrete melatonin (the hormone that regulates the wake-sleep cycle) later than when they were children.
Forcing teenagers to be awake early in the morning, and start school at 7:10 am does not mean that they will go to bed early at night. In fact, the opposite happens: they still go to sleep late at night as their bodies dictate, but now they wake up too early without having slept enough. The schoolday becomes a chore because they are tired.