Sometimes it's simply not possible to get a dog to "go" where you want it to. Just like some people have to sit on the toilet for awhile before any action happens, some dogs need a walk to get things going. And in many campgrounds there is so little common space that it's next to impossible to avoid a dog going on another camper's site.
I personally don't have a problem with it as long as the owner cleans up. As others have said, in all likelihood there are birds and squirrels and possibly even othe wildlife regularly peeing and pooping on any given site.
I'm sorry your former dog's output smelled so bad. Many dogs who are fed a food that doesn't agree with them (whether it's a cheap food or a very good quality food) have that problem. The stool of a dog who is fed a food that agrees with him, and who has no other GI issue, should be firm and well formed and easy to pick up and it shouldn't be very smelly at all.
