Clubs can do a better job communicating this to their parents - especially Novice when so much is already new. But to retrain Open families, Tournaments should communicate and enforce better too. No one wants to be the hall monitor, so empower all volunteers around tables to tell folks with a smile - families return to your seats, only coaches matside and please stay down.
From the parent perspective, I've been guilty staying matside after walking my little kids to the mat. Even though I was quiet and kept out of the way, my kids could see me not following instructions, as I want them to do. Getting away with something is not the message I want them to get.
Always going to be folks who don't listen or care. But if we set the expectation, clubs remind families to be respectful and they represent their club, it's a start.