This has always been a problem in very popular places near populous areas. The wonderful thing about being "empty nesters" is that we can avoid the party weekends. So for the most part we don't encounter the "trash people". 3Oaks, that's not to say that all are slobs, I get what you are saying, but in my observation in nearly 30 years of doing this is that there seems to be this mentality among those going on 3 day holiday weekends, that "I must have a good time" at any cost.
One way to avoid seeing a lot of this is to go hiking or biking on off road trails. People who are there to party generally don't like to put physical effort into things, so all you'll encounter on the trails is like minded people.
That said every place we've been to that caters to hikers and true outdoors people does not seem to have this issue.