"Quietness" is kind of fake-out anyway.
We don't want a lot of folks around us when we're camping - quiet or otherwise. We want to actually be out in nature when camping - not in campurbia where an illusion of being by yourself has to be artificially created by establishing a limited time-period called "quiet hours". We'd like campgrounds to have a lot more spacing between sites so "quietness" was not such a big issue. Some public campgrounds have sites with close to this environment around them, but only very, very rarely.
I guess that's one of the advantages of being close to Western U.S. camping areas ... you can easily get to spots where the only "noise" is your own.