While I am mostly a jeep driver/passenger while at URE, I have gone atleast 4x and brought a dirtbike or the atv, the only atv I have ever ran at URE was a banshee, and its damn loud and obnoxious when I want it to be, what the OP was referring to wasn't riding thru the campground area, it was revving up in the campground area because you think everyone will enjoy the sound of your vehicle. Same goes for your rig, if your romping the hell out of it in the campground area, or just revving it up for the "cool factor" thats annoying as hell too.
Golden rule, treat others as you would want to be treated. Chances are you wouldn't enjoy some random guy in a rig with a V8 sitting 15-20 feet from your campsite revving his engine, roostin tires, or other rude things while you and your family are trying to eat and talk, it isn't much to expect them to keep the RPMS low while they pass through and back onto the trails. Respect the trails, Respect the other people who share your interest in the trails, whether your an ATV'er, or you wheel a jeep/toyota/ford/chevy/dodge/isuzu/ honda/lexus/whatever... The people you meet on the trails share an interest, and they are probably some of the friendliest folks you will meet.
Having met Chip, Upnover at the flats once, I can speak from experience that he was very helpful, he didn't know us but was quick to offer his assistance, and I imagine he would be like that toward an ATV'er too if they had an issue. So are most I have met off this forum.
Just my opinion, don't want to ruffle anyones feathers, but we all need to work together to keep the trails open, and arguing and bickering and fighting about everything isn't going to get us anywhere.
Personally, I don't care if your wearing a helmet for any other reason than if you get hurt/die because of your own stupidity, it would look bad for the trails. Same goes for people not wearing seatbelts.