Above posts are on point. Definition of "Horror stories" is different from one person to another.
Some campgrounds are spaced close together, others offer some privacy and that alone can make a big difference.
We enjoy taking our grandkids camping in the summer months and stay with them. A small number of kids in campgrounds run wild, act disrespectful and do whatever they want... but most are good kids.
Some adults (young and older) are on vacation and decide to use the campground as party place... loud/rude/up late etc. This happens anywhere, at any time.
If you have concerns about a popular area, do some homework to target Adult only Parks, stay a bit off the beaten track or whatever fits the bill.
From a personal perspective it seems to us the Western USA has more campgrounds/RV Parks available than the East and East Coast.
With that said, we have not done a comparison and this is not intended as a blanket statement.
We have lived our entire lives on the east coast. It can be frustrating that some beautiful area's in the East have few options to camp and in many cases few to no options to Boondock. With the few campgrounds available, those available can be prone to overcrowding.
Our travels in western states, it has been easy to find wonderful camping locations at all times of the year.