Everyone is looking for a nice, hidden oasis when they go on a camping trip...far away from other people. There is no limit to the excitement of finding the perfect, hidden spot. However, you usually don't want to want to share that secret with everyone, or else it will soon become not quite as secretive. This sign sort of defeats the purpose of it being a hidden campground when it displays the exact location for everyone.
It does appear to be a pretty overgrown area and maybe the campground will still be difficult to find for most people, despite the sign. Hopefully, the secret campground will not be too full of people!