The fact that blacks don't camp doesn't mean usage of parks isn't "diverse", though I don't know why that matters. Midnight basketball isn't diverse either. I've noted large national parks often have substatial numbers of asian and european visitors. I sometimes wonder why more Americans don't visit
We have nice parks in NJ and neighboring NY (including beaches), but there is little money to maintain them. Some look abandoned, and services are cut; Hurricanes Irene and Sandy did some damage that is still not addressed (and can’t be for lack of funds).
During decent weather, the areas most heavily used by non-Anglos look like a bomb was dropped on a garbage dump; absolutely filthy. The only solution is to charge higher fees, which politically doesn’t sell well.
The first sentence answers the second for me.