It's a tough time of year, with lots of inexperienced campers out there. In the campground where we spend the summer, it's quite crowded through July and August. There are plenty of rangers out there and they do a pretty good job of catching and warning drivers that exceed the 10mph limit. We see some speeding, but not all that much.
In reality, it's great that they do enforce it, because kids running around and on bikes seem almost oblivious to their surroundings. There would be lots of injured kids, if the speed limits were allowed to be ignored.
When we have our grand kids over, we stress to them that the CG roads should be treated just like driving on public streets and they need to pay attention!