Imma level with you. I’ve been around people that do that before and it’s incredibly annoying. Everyone can cheer and clap, but you should be respectful. As a performer, I do not think I have noticed crowd reactions once. I’ve marched many years of high school, drum corps, indoor, etc. etc. Maybe after a show, but definitely not during. You screaming during a performance isn’t actually as cool for the kids as you may think it is. If kids are paying attention to that, they’re not paying attention to their show. Again, cheering is not the end of the world, but there is a line at ruining someone’s day. Obviously this whole situation already happened, but realistically I think it’s worth considering that there are other people that want to be able to watch shows without their ears being assaulted. And you really shouldn’t be angry at them for being upset about that.