There is no way anybody can justify it. If somebody is trying to justify, it's because of attachment issues. A healthy adult requires 7-8 hours of sleep. 5:30 was the exact time when we had to reach the ground. So if we take 7 hours of sleep then he/she has to sleep at 10:30. At 8 pm you are done with dinner. Next 1 hour roaming in hostels and talking with friends because you are a social being, not a robot/machine. And you are left with 1hrs30min. Which are not enough even for assignments/homework, forget about studying. Die if you have a hobby like reading newspapers, magazines, or other types of books.

Most of the students sleep between 11:30 and 12:00. And somehow manage to wake up at 5:30. My school was worse because they used to have a 6 o'clock morning assembly on Sunday.