<< The proprietor of a theater can impose whatever policies he or she wishes, but as a practical matter you are barking up the wrong tree. If a given theater sets a policy of letting people in, in violation of MPAA guidelines, they face losing distribution from the studios and distributors, to say nothing of opening themselves up to community protests, etc. >>
The guideline was and is that someone under 17 has to be accompanied by an adult. We were in a group of people, the oldest of whom was 20. This was also before it became "trendy" to ban minors from the theatre, in fact it was the first I'd heard of it in my town.
<< Your diatribe against the theater manager sounds amazingly juvenile and unnecessarily personal. >>
I was 17. Sue me.