Do you want someone controlling your plane who can't handle waking up early? Air traffic control is 24 hours a day 7 days week; you will be working at all hours of the day.
I would rather have someone who has no problem staying up late rather than someone who is a 'morning person'. Once awake, night owls seems to be better at staying awake.
No, I don't. I want outliers, people who have extraordinary ability to function at all times of the day.
I want the 20% exceptions that make it, not the 80% average folks who drop out.