It may also be that they just want to keep the riff-raff in tents out.
Without actually have a "No Tents" rule - which lots of private campgrounds now have.
When you drop $350,000 for an RV, you don't want some people in an old Honda with a tent next to you.
I am of a certain vintage where I remember when 90% of the folks camping were tenting.
The people with trailers - and they were called trailers then - had small, sometimes homemade, units.
Now, quite a few state parks have all pull-thru sites with electricity, water & sewer. Sometimes even cable.
And, despite the quiet hours, the generators or at least the ACs run all night.
Not quite sure why they still use the term "camping".
Yes, there are a few public camp sites in the Delaware Water Gap area with moderate rates.
But in places like northern Ohio & Indiana, nearly all of the camping is private, pricey, and packed-in.
The few natural lakes in the lower Midwest have every inch of lakefront lined with summer cottages.
Maybe we should just sell lots on the edge of the Grand Canyon to pay off the national debt, eh?