Not really stupid. Annoying for 16/17 year olds but not stupid. CA labor law prohibits minors from working past 10:00PM on Wed, Thu and Sun and after 12:30 Fri and Sat. Sure, Universal could monitor minors and make sure they leave by 10PM but that creates major difficulties in scheduling. And legal problems if they make a mistake and violate the labor laws.
Who here is going to audition?